map: When removing a key, don't NULL the entry, but mark as deleted.
map: When removing a key, don't NULL the entry, but mark as deleted.

When searching next time, such entry should be just skipped, not terminate
the search. It's known that marking techique is not efficient at the presense
of many removes, but namespace usage should not require many deletes, and
as for user dictionaries - well, open addressing map table with linear
rehashing and load factor of ~1 is not particularly efficient at all ;-).
TODO: May consider "shift other entries in cluster" approach as an
alternative.

SHA2017-badge/micropython-esp32,deshipu/micropython,rubencabrera/micropython,dxxb/micropython,supergis/micropython,HenrikSolver/micropython,mianos/micropython,noahchense/micropython,turbinenreiter/micropython,ChuckM/micropython,heisewangluo/micropython,mianos/micropython,kostyll/micropython,SHA2017-badge/micropython-esp32,alex-march/micropython,kostyll/micropython,orionrobots/micropython,swegener/micropython,KISSMonX/micropython,noahchense/micropython,torwag/micropython,jimkmc/micropython,ryannathans/micropython,vriera/micropython,infinnovation/micropython,heisewangluo/micropython,cloudformdesign/micropython,jimkmc/micropython,Vogtinator/micropython,xuxiaoxin/micropython,puuu/micropython,vitiral/micropython,AriZuu/micropython,adamkh/micropython,tuc-osg/micropython,neilh10/micropython,matthewelse/micropython,feilongfl/micropython,vitiral/micropython,stonegithubs/micropython,cwyark/micropython,Timmenem/micropython,orionrobots/micropython,HenrikSolver/micropython,xyb/micropython,ahotam/micropython,ernesto-g/micropython,alex-march/micropython,suda/micropython,jmarcelino/pycom-micropython,lbattraw/micropython,noahwilliamsson/micropython,MrSurly/micropython-esp32,drrk/micropython,xuxiaoxin/micropython,tralamazza/micropython,emfcamp/micropython,martinribelotta/micropython,firstval/micropython,dinau/micropython,EcmaXp/micropython,chrisdearman/micropython,firstval/micropython,Peetz0r/micropython-esp32,stonegithubs/micropython,cwyark/micropython,supergis/micropython,torwag/micropython,mhoffma/micropython,blazewicz/micropython,bvernoux/micropython,EcmaXp/micropython,ericsnowcurrently/micropython,PappaPeppar/micropython,torwag/micropython,matthewelse/micropython,adafruit/circuitpython,SungEun-Steve-Kim/test-mp,alex-robbins/micropython,hiway/micropython,rubencabrera/micropython,praemdonck/micropython,ChuckM/micropython,turbinenreiter/micropython,blmorris/micropython,Vogtinator/micropython,TDAbboud/micropython,tobbad/micropython,hosaka/micropython,alex-march/micropython,bvernoux/micropython,trezor/micropython,ryannathans/micropython,praemdonck/micropython,feilongfl/micropython,xuxiaoxin/micropython,omtinez/micropython,ernesto-g/micropython,deshipu/micropython,dinau/micropython,xyb/micropython,adamkh/micropython,aethaniel/micropython,MrSurly/micropython,henriknelson/micropython,mgyenik/micropython,suda/micropython,pozetroninc/micropython,ruffy91/micropython,tuc-osg/micropython,bvernoux/micropython,vriera/micropython,dhylands/micropython,MrSurly/micropython,noahchense/micropython,dmazzella/micropython,danicampora/micropython,mianos/micropython,EcmaXp/micropython,dhylands/micropython,feilongfl/micropython,pozetroninc/micropython,selste/micropython,redbear/micropython,jlillest/micropython,cwyark/micropython,tralamazza/micropython,ernesto-g/micropython,PappaPeppar/micropython,mhoffma/micropython,noahwilliamsson/micropython,henriknelson/micropython,swegener/micropython,tralamazza/micropython,tdautc19841202/micropython,jimkmc/micropython,blmorris/micropython,jmarcelino/pycom-micropython,Timmenem/micropython,rubencabrera/micropython,swegener/micropython,mianos/micropython,omtinez/micropython,alex-robbins/micropython,dinau/micropython,kostyll/micropython,mpalomer/micropython,tdautc19841202/micropython,pozetroninc/micropython,aethaniel/micropython,ruffy91/micropython,ernesto-g/micropython,warner83/micropython,dmazzella/micropython,drrk/micropython,vriera/micropython,ceramos/micropython,praemdonck/micropython,mpalomer/micropython,drrk/micropython,bvernoux/micropython,adafruit/circuitpython,feilongfl/micropython,kerneltask/micropython,utopiaprince/micropython,pramasoul/micropython,selste/micropython,MrSurly/micropython-esp32,chrisdearman/micropython,ganshun666/micropython,tdautc19841202/micropython,hosaka/micropython,xuxiaoxin/micropython,mhoffma/micropython,HenrikSolver/micropython,orionrobots/micropython,supergis/micropython,methoxid/micropystat,dhylands/micropython,MrSurly/micropython-esp32,kerneltask/micropython,xyb/micropython,ernesto-g/micropython,mpalomer/micropython,Timmenem/micropython,ganshun666/micropython,emfcamp/micropython,ceramos/micropython,SHA2017-badge/micropython-esp32,cwyark/micropython,oopy/micropython,martinribelotta/micropython,matthewelse/micropython,misterdanb/micropython,adafruit/circuitpython,noahchense/micropython,toolmacher/micropython,skybird6672/micropython,infinnovation/micropython,pramasoul/micropython,TDAbboud/micropython,adamkh/micropython,AriZuu/micropython,ahotam/micropython,turbinenreiter/micropython,deshipu/micropython,dmazzella/micropython,noahchense/micropython,slzatz/micropython,mhoffma/micropython,MrSurly/micropython-esp32,SHA2017-badge/micropython-esp32,noahwilliamsson/micropython,henriknelson/micropython,misterdanb/micropython,toolmacher/micropython,xhat/micropython,pramasoul/micropython,jlillest/micropython,ahotam/micropython,cloudformdesign/micropython,pozetroninc/micropython,jlillest/micropython,utopiaprince/micropython,ryannathans/micropython,alex-march/micropython,deshipu/micropython,HenrikSolver/micropython,trezor/micropython,martinribelotta/micropython,drrk/micropython,Vogtinator/micropython,aethaniel/micropython,cnoviello/micropython,Peetz0r/micropython-esp32,skybird6672/micropython,dxxb/micropython,galenhz/micropython,Peetz0r/micropython-esp32,aitjcize/micropython,aethaniel/micropython,ahotam/micropython,oopy/micropython,Vogtinator/micropython,cnoviello/micropython,vitiral/micropython,tralamazza/micropython,oopy/micropython,omtinez/micropython,lbattraw/micropython,lowRISC/micropython,methoxid/micropystat,kostyll/micropython,turbinenreiter/micropython,paul-xxx/micropython,hosaka/micropython,lbattraw/micropython,vitiral/micropython,EcmaXp/micropython,KISSMonX/micropython,jmarcelino/pycom-micropython,jimkmc/micropython,pfalcon/micropython,ChuckM/micropython,warner83/micropython,emfcamp/micropython,Timmenem/micropython,xyb/micropython,neilh10/micropython,SungEun-Steve-Kim/test-mp,lowRISC/micropython,cloudformdesign/micropython,rubencabrera/micropython,SHA2017-badge/micropython-esp32,drrk/micropython,ryannathans/micropython,methoxid/micropystat,alex-robbins/micropython,misterdanb/micropython,jmarcelino/pycom-micropython,micropython/micropython-esp32,ChuckM/micropython,vitiral/micropython,dhylands/micropython,MrSurly/micropython,utopiaprince/micropython,mgyenik/micropython,jmarcelino/pycom-micropython,micropython/micropython-esp32,misterdanb/micropython,stonegithubs/micropython,pramasoul/micropython,suda/micropython,skybird6672/micropython,hiway/micropython,TDAbboud/micropython,trezor/micropython,blazewicz/micropython,emfcamp/micropython,slzatz/micropython,deshipu/micropython,chrisdearman/micropython,ceramos/micropython,lowRISC/micropython,xhat/micropython,galenhz/micropython,adafruit/micropython,toolmacher/micropython,warner83/micropython,omtinez/micropython,skybird6672/micropython,infinnovation/micropython,henriknelson/micropython,MrSurly/micropython,mgyenik/micropython,xhat/micropython,xhat/micropython,micropython/micropython-esp32,stonegithubs/micropython,aitjcize/micropython,utopiaprince/micropython,pfalcon/micropython,torwag/micropython,hiway/micropython,kerneltask/micropython,dmazzella/micropython,blazewicz/micropython,cloudformdesign/micropython,vriera/micropython,aethaniel/micropython,paul-xxx/micropython,firstval/micropython,mpalomer/micropython,mpalomer/micropython,tobbad/micropython,ericsnowcurrently/micropython,torwag/micropython,tdautc19841202/micropython,mgyenik/micropython,selste/micropython,suda/micropython,pramasoul/micropython,ruffy91/micropython,xhat/micropython,slzatz/micropython,danicampora/micropython,galenhz/micropython,SungEun-Steve-Kim/test-mp,jlillest/micropython,redbear/micropython,galenhz/micropython,hiway/micropython,supergis/micropython,PappaPeppar/micropython,heisewangluo/micropython,praemdonck/micropython,alex-march/micropython,cnoviello/micropython,AriZuu/micropython,matthewelse/micropython,ChuckM/micropython,HenrikSolver/micropython,martinribelotta/micropython,adafruit/circuitpython,dxxb/micropython,tuc-osg/micropython,adafruit/circuitpython,oopy/micropython,dinau/micropython,tobbad/micropython,hosaka/micropython,mhoffma/micropython,AriZuu/micropython,SungEun-Steve-Kim/test-mp,neilh10/micropython,chrisdearman/micropython,mianos/micropython,heisewangluo/micropython,Vogtinator/micropython,toolmacher/micropython,trezor/micropython,ryannathans/micropython,orionrobots/micropython,dxxb/micropython,dinau/micropython,ericsnowcurrently/micropython,methoxid/micropystat,slzatz/micropython,adamkh/micropython,puuu/micropython,puuu/micropython,pfalcon/micropython,AriZuu/micropython,MrSurly/micropython,danicampora/micropython,redbear/micropython,blmorris/micropython,matthewelse/micropython,adamkh/micropython,trezor/micropython,cnoviello/micropython,kerneltask/micropython,vriera/micropython,adafruit/micropython,lowRISC/micropython,dhylands/micropython,stonegithubs/micropython,paul-xxx/micropython,tuc-osg/micropython,cloudformdesign/micropython,ericsnowcurrently/micropython,mgyenik/micropython,emfcamp/micropython,ganshun666/micropython,martinribelotta/micropython,neilh10/micropython,xuxiaoxin/micropython,swegener/micropython,lbattraw/micropython,adafruit/micropython,kerneltask/micropython,slzatz/micropython,neilh10/micropython,ceramos/micropython,orionrobots/micropython,aitjcize/micropython,xyb/micropython,ceramos/micropython,paul-xxx/micropython,TDAbboud/micropython,methoxid/micropystat,ahotam/micropython,adafruit/micropython,micropython/micropython-esp32,misterdanb/micropython,redbear/micropython,MrSurly/micropython-esp32,aitjcize/micropython,rubencabrera/micropython,paul-xxx/micropython,toolmacher/micropython,dxxb/micropython,skybird6672/micropython,warner83/micropython,puuu/micropython,puuu/micropython,adafruit/circuitpython,matthewelse/micropython,jlillest/micropython,EcmaXp/micropython,bvernoux/micropython,ericsnowcurrently/micropython,firstval/micropython,pfalcon/micropython,pozetroninc/micropython,lowRISC/micropython,KISSMonX/micropython,selste/micropython,tobbad/micropython,infinnovation/micropython,firstval/micropython,henriknelson/micropython,Peetz0r/micropython-esp32,tdautc19841202/micropython,TDAbboud/micropython,feilongfl/micropython,heisewangluo/micropython,ruffy91/micropython,swegener/micropython,blmorris/micropython,infinnovation/micropython,noahwilliamsson/micropython,chrisdearman/micropython,hosaka/micropython,noahwilliamsson/micropython,blazewicz/micropython,Timmenem/micropython,redbear/micropython,alex-robbins/micropython,Peetz0r/micropython-esp32,KISSMonX/micropython,danicampora/micropython,pfalcon/micropython,SungEun-Steve-Kim/test-mp,kostyll/micropython,suda/micropython,utopiaprince/micropython,tuc-osg/micropython,blmorris/micropython,PappaPeppar/micropython,selste/micropython,ganshun666/micropython,oopy/micropython,tobbad/micropython,PappaPeppar/micropython,galenhz/micropython,turbinenreiter/micropython,adafruit/micropython,hiway/micropython,alex-robbins/micropython,cwyark/micropython,warner83/micropython,omtinez/micropython,lbattraw/micropython,praemdonck/micropython,blazewicz/micropython,supergis/micropython,danicampora/micropython,cnoviello/micropython,KISSMonX/micropython,ruffy91/micropython,micropython/micropython-esp32,jimkmc/micropython,ganshun666/micropython