esp8266/scripts/onewire.py: Simplify and improve 1-wire driver.
esp8266/scripts/onewire.py: Simplify and improve 1-wire driver.

Changes are:
- added OneWireError exception and used where errors can occur
- renamed read/write functions to use same names as C _onewire funcs
- read_bytes is now read, write_bytes is now write
- add ability to read/write DS18B20 scratch pad
- rename start_measure to convert_temp (since that's what it does)
- rename get_temp to read_temp (consistency with other read names)
- removed test function

toolmacher/micropython,HenrikSolver/micropython,pramasoul/micropython,puuu/micropython,jmarcelino/pycom-micropython,Timmenem/micropython,ryannathans/micropython,tuc-osg/micropython,selste/micropython,blazewicz/micropython,henriknelson/micropython,HenrikSolver/micropython,deshipu/micropython,misterdanb/micropython,drrk/micropython,dinau/micropython,bvernoux/micropython,AriZuu/micropython,Timmenem/micropython,chrisdearman/micropython,deshipu/micropython,emfcamp/micropython,TDAbboud/micropython,cwyark/micropython,cwyark/micropython,adafruit/circuitpython,micropython/micropython-esp32,dmazzella/micropython,selste/micropython,MrSurly/micropython,lowRISC/micropython,adafruit/circuitpython,alex-march/micropython,SHA2017-badge/micropython-esp32,adafruit/micropython,drrk/micropython,mhoffma/micropython,Timmenem/micropython,chrisdearman/micropython,misterdanb/micropython,turbinenreiter/micropython,blazewicz/micropython,AriZuu/micropython,adafruit/micropython,pramasoul/micropython,kerneltask/micropython,praemdonck/micropython,torwag/micropython,dmazzella/micropython,adafruit/micropython,ganshun666/micropython,pfalcon/micropython,swegener/micropython,dmazzella/micropython,deshipu/micropython,blazewicz/micropython,oopy/micropython,matthewelse/micropython,toolmacher/micropython,jmarcelino/pycom-micropython,emfcamp/micropython,tobbad/micropython,selste/micropython,dxxb/micropython,redbear/micropython,emfcamp/micropython,AriZuu/micropython,oopy/micropython,alex-march/micropython,swegener/micropython,infinnovation/micropython,toolmacher/micropython,torwag/micropython,SHA2017-badge/micropython-esp32,SHA2017-badge/micropython-esp32,tuc-osg/micropython,mhoffma/micropython,puuu/micropython,dxxb/micropython,selste/micropython,micropython/micropython-esp32,PappaPeppar/micropython,henriknelson/micropython,bvernoux/micropython,hosaka/micropython,toolmacher/micropython,emfcamp/micropython,matthewelse/micropython,misterdanb/micropython,ganshun666/micropython,kerneltask/micropython,infinnovation/micropython,emfcamp/micropython,misterdanb/micropython,MrSurly/micropython-esp32,HenrikSolver/micropython,lowRISC/micropython,henriknelson/micropython,pramasoul/micropython,mpalomer/micropython,jmarcelino/pycom-micropython,torwag/micropython,bvernoux/micropython,swegener/micropython,MrSurly/micropython-esp32,MrSurly/micropython-esp32,infinnovation/micropython,tuc-osg/micropython,hiway/micropython,cwyark/micropython,pozetroninc/micropython,micropython/micropython-esp32,mhoffma/micropython,trezor/micropython,trezor/micropython,hosaka/micropython,PappaPeppar/micropython,mpalomer/micropython,MrSurly/micropython,mpalomer/micropython,turbinenreiter/micropython,cwyark/micropython,ryannathans/micropython,hiway/micropython,Peetz0r/micropython-esp32,praemdonck/micropython,tralamazza/micropython,SHA2017-badge/micropython-esp32,TDAbboud/micropython,puuu/micropython,MrSurly/micropython-esp32,cwyark/micropython,kerneltask/micropython,tobbad/micropython,puuu/micropython,hiway/micropython,dxxb/micropython,swegener/micropython,chrisdearman/micropython,dinau/micropython,lowRISC/micropython,adafruit/circuitpython,drrk/micropython,MrSurly/micropython,adafruit/circuitpython,torwag/micropython,tobbad/micropython,TDAbboud/micropython,pramasoul/micropython,turbinenreiter/micropython,ganshun666/micropython,pozetroninc/micropython,adafruit/circuitpython,ryannathans/micropython,deshipu/micropython,puuu/micropython,HenrikSolver/micropython,dinau/micropython,PappaPeppar/micropython,tralamazza/micropython,TDAbboud/micropython,Peetz0r/micropython-esp32,pfalcon/micropython,hosaka/micropython,hiway/micropython,oopy/micropython,mpalomer/micropython,micropython/micropython-esp32,torwag/micropython,adafruit/circuitpython,tuc-osg/micropython,henriknelson/micropython,MrSurly/micropython-esp32,praemdonck/micropython,pfalcon/micropython,kerneltask/micropython,henriknelson/micropython,Timmenem/micropython,AriZuu/micropython,infinnovation/micropython,TDAbboud/micropython,ryannathans/micropython,chrisdearman/micropython,tuc-osg/micropython,trezor/micropython,matthewelse/micropython,Timmenem/micropython,pfalcon/micropython,redbear/micropython,hiway/micropython,MrSurly/micropython,deshipu/micropython,selste/micropython,PappaPeppar/micropython,pramasoul/micropython,drrk/micropython,redbear/micropython,oopy/micropython,tralamazza/micropython,drrk/micropython,redbear/micropython,praemdonck/micropython,blazewicz/micropython,alex-march/micropython,redbear/micropython,misterdanb/micropython,pozetroninc/micropython,AriZuu/micropython,bvernoux/micropython,mhoffma/micropython,adafruit/micropython,SHA2017-badge/micropython-esp32,adafruit/micropython,blazewicz/micropython,alex-robbins/micropython,Peetz0r/micropython-esp32,matthewelse/micropython,lowRISC/micropython,dmazzella/micropython,kerneltask/micropython,alex-robbins/micropython,dxxb/micropython,pfalcon/micropython,matthewelse/micropython,turbinenreiter/micropython,HenrikSolver/micropython,infinnovation/micropython,dxxb/micropython,dinau/micropython,jmarcelino/pycom-micropython,alex-march/micropython,ryannathans/micropython,tobbad/micropython,alex-robbins/micropython,MrSurly/micropython,trezor/micropython,swegener/micropython,toolmacher/micropython,alex-robbins/micropython,tralamazza/micropython,alex-robbins/micropython,lowRISC/micropython,dinau/micropython,bvernoux/micropython,pozetroninc/micropython,matthewelse/micropython,oopy/micropython,Peetz0r/micropython-esp32,turbinenreiter/micropython,pozetroninc/micropython,alex-march/micropython,Peetz0r/micropython-esp32,mpalomer/micropython,jmarcelino/pycom-micropython,ganshun666/micropython,micropython/micropython-esp32,praemdonck/micropython,ganshun666/micropython,tobbad/micropython,trezor/micropython,hosaka/micropython,chrisdearman/micropython,PappaPeppar/micropython,hosaka/micropython,mhoffma/micropython