Update shiftSelecting from event in onMouseDown
Update shiftSelecting from event in onMouseDown

Closes #255

increpare/CodeMirror,sekcheong/CodeMirror,amshali/CodeMirror,antimatter15/CodeMirror,abdelouahabb/CodeMirror,matthewbauer/CodeMirror,Dominator008/CodeMirror,amshali/CodeMirror,bfrohs/CodeMirror,angelozerr/CodeMirror,hccampos/CodeMirror,bocharsky-bw/CodeMirror,INTELOGIE/CodeMirror,r7kamura/CodeMirror,rustemferreira/CodeMirror,michaelerobertsjr/CodeMirror,Jisuanke/CodeMirror,jkaplon/CodeMirror,filonb/CodeMirror2,kuangyeheng/CodeMirror,trumanliu/CodeMirror,kk9599/CodeMirror,wbinnssmith/CodeMirror,mightyguava/CodeMirror,pabloferz/CodeMirror,rasata/CodeMirror,dbarnett/CodeMirror,ThebingServices/CodeMirror,ashmind/CodeMirror,gkoberger/CodeMirror,webida/CodeMirror,ksanaforge/CodeMirror,morrisonwudi/CodeMirror,d0liver/CodeMirror,shiren/CodeMirror,amsul/CodeMirror,axter/CodeMirror,rrandom/CodeMirror,happibum/CodeMirror-main,dudb/CodeMirror,Jisuanke/CodeMirror,MarcelGerber/CodeMirror,bocharsky-bw/CodeMirror,r7kamura/CodeMirror,codio/CodeMirror,tpphu/CodeMirror,KamranMackey/CodeMirror,philuchansky/CodeMirror,jhnesk/CodeMirror,djadmin/CodeMirror,namin/CodeMirror,TDaglis/CodeMirror,xeronith/CodeMirror,fmoliveira/CodeMirror,mihailik/CodeMirror,bluesh55/CodeMirror,Carreau/CodeMirror,jkaplon/CodeMirror,michaelerobertsjr/CodeMirror,sourcelair/CodeMirror,vincentwoo/CodeMirror,InternetGuru/CodeMirror,fivetran/CodeMirror,sekcheong/CodeMirror,anthonygego/CodeMirror,namin/CodeMirror,grzegorzmazur/CodeMirror,trumanliu/CodeMirror,jhnesk/CodeMirror,schanzer/CodeMirror,manderson23/CodeMirror,adobe/CodeMirror2,manderson23/CodeMirror,SidPresse/CodeMirror,sourcelair/CodeMirror,rrandom/CodeMirror,apatawari/CodeMirror,cintiamh/CodeMirror,kolya-ay/CodeMirror,rasata/CodeMirror,jessegrosjean/CodeMirror,fmoliveira/CodeMirror,belph/CodeMirror,jansel/CodeMirror,ejgallego/CodeMirror,GerHobbelt/CodeMirror2,wbinnssmith/CodeMirror,alur/CodeMirror,kolya-ay/CodeMirror,vincentwoo/CodeMirror,ZombieHippie/CodeMirror,bgrins/CodeMirror,Navaneethsen/CodeMirror,kerabromsmu/CodeMirror,MarcelGerber/CodeMirror,Allenice/CodeMirror,camellhf/CodeMirror,rasata/CodeMirror,kerabromsmu/CodeMirror,axter/CodeMirror,abdelouahabb/CodeMirror,Aliccer/CodeMirror,isdampe/CodeMirror,Dominator008/CodeMirror,qiankun007/CodeMirror,AlanWasTaken/codemirror,angelozerr/CodeMirror,ThebingServices/CodeMirror,pabloferz/CodeMirror,davidpham87/CodeMirror,SidPresse/CodeMirror,webida/CodeMirror,nightwing/CodeMirror,mtaran-google/CodeMirror,kk9599/CodeMirror,supriyantomaftuh/CodeMirror,nightwing/CodeMirror,dudb/CodeMirror,supriyantomaftuh/CodeMirror,NumbersInternational/CodeMirror,NeZaMy/CodeMirror2,ashmind/CodeMirror,vincentwoo/CodeMirror,Navaneethsen/CodeMirror,INTELOGIE/CodeMirror,ksanaforge/CodeMirror,TechnicalPursuit/CodeMirror,hccampos/CodeMirror,hackmdio/CodeMirror,mizchi/CodeMirror,karthikeyansam/CodeMirror,anthonygego/CodeMirror,sekcheong/CodeMirror,xeronith/CodeMirror,mightyguava/CodeMirror,NumbersInternational/CodeMirror,notepadqq/CodeMirror,karevn/CodeMirror,jochenberger/CodeMirror,camellhf/CodeMirror,skylarkcob/CodeMirror,leoshine/CodeMirror,KamranMackey/CodeMirror,melpon/CodeMirror,pinbe/CodeMirror,jochenberger/CodeMirror,sanyaade-iot/CodeMirror,codio/CodeMirror,bocharsky-bw/CodeMirror,nawroth/CodeMirror,vanloswang/CodeMirror,djadmin/CodeMirror,melpon/CodeMirror,sanyaade-iot/CodeMirror,Ermlab/CodeMirror,jpolitz/CodeMirror,DustinH/CodeMirror,femhub/CodeMirror2,mihailik/CodeMirror,joshterrell805-historic/CodeMirror,flyskyko/CodeMirror,mtaran-google/CodeMirror,kerabromsmu/CodeMirror,notepadqq/CodeMirror,Icenium/CodeMirror,sourcelair/CodeMirror,ejgallego/CodeMirror,kangkot/CodeMirror,sgoo/CodeMirror,ssxxue/CodeMirror,thomasjm/CodeMirror,apatawari/CodeMirror,EasonYi/CodeMirror,explorigin/CodeMirror,pjkui/CodeMirror,melpon/CodeMirror,crazy4chrissi/CodeMirror,TechnicalPursuit/CodeMirror,increpare/CodeMirror,webida/CodeMirror,mizchi/CodeMirror,pjkui/CodeMirror,ssxxue/CodeMirror,rustemferreira/CodeMirror,d0liver/CodeMirror,philuchansky/CodeMirror,buchslava/CodeMirror,qiankun007/CodeMirror,amireh/codemirror,InternetGuru/CodeMirror,joshterrell805-historic/CodeMirror,Allenice/CodeMirror,bgrins/CodeMirror,MarcelGerber/CodeMirror,ZombieHippie/CodeMirror,explorigin/CodeMirror,NumbersInternational/CodeMirror,thomasjm/CodeMirror,codio/CodeMirror,dbarnett/CodeMirror,davidpham87/CodeMirror,Icenium/CodeMirror,nawroth/CodeMirror,INTELOGIE/CodeMirror,cintiamh/CodeMirror,abdelouahabb/CodeMirror,TDaglis/CodeMirror,EasonYi/CodeMirror,rustemferreira/CodeMirror,femhub/CodeMirror2,matthewbauer/CodeMirror,CartoDB/CodeMirror,schanzer/CodeMirror,sanyaade-iot/CodeMirror,kangkot/CodeMirror,filonb/CodeMirror2,pinbe/CodeMirror,symbla/CodeMirror,systay/CodeMirror,grzegorzmazur/CodeMirror,kk9599/CodeMirror,Aliccer/CodeMirror,qweasd1/CodeMirror,hackmdio/CodeMirror,Jisuanke/CodeMirror,fivetran/CodeMirror,agendor/CodeMirror,kevinushey/CodeMirror,TDaglis/CodeMirror,Icenium/CodeMirror,gkoberger/CodeMirror,jayaprabhakar/CodeMirror,dbarnett/CodeMirror,gkoberger/CodeMirror,cben/CodeMirror,fpco/codemirror,ZombieHippie/CodeMirror,femhub/CodeMirror2,increpare/CodeMirror,jayaprabhakar/CodeMirror,schanzer/CodeMirror,KamranMackey/CodeMirror,belph/CodeMirror,DustinH/CodeMirror,axter/CodeMirror,cben/CodeMirror,mtaran-google/CodeMirror,systay/CodeMirror,djadmin/CodeMirror,karevn/CodeMirror,skylarkcob/CodeMirror,ashmind/CodeMirror,isdampe/CodeMirror,happibum/CodeMirror-main,loopspace/CodeMirror,karthikeyansam/CodeMirror,mizchi/CodeMirror,bfrohs/CodeMirror,jpolitz/CodeMirror,elisee/CodeMirror,TechnicalPursuit/CodeMirror,karthikeyansam/CodeMirror,skylarkcob/CodeMirror,dperetti/CodeMirror,wingify/CodeMirror,fmoliveira/CodeMirror,vanloswang/CodeMirror,tpphu/CodeMirror,grzegorzmazur/CodeMirror,camellhf/CodeMirror,dperetti/CodeMirror,NeZaMy/CodeMirror2,manderson23/CodeMirror,symbla/CodeMirror,mihailik/CodeMirror,philuchansky/CodeMirror,Aliccer/CodeMirror,shiren/CodeMirror,alur/CodeMirror,amsul/CodeMirror,jpolitz/CodeMirror,supriyantomaftuh/CodeMirror,bluesh55/CodeMirror,AlanWasTaken/codemirror,sgoo/CodeMirror,pjkui/CodeMirror,DustinH/CodeMirror,belph/CodeMirror,bfrohs/CodeMirror,kangkot/CodeMirror,hackmdio/CodeMirror,qiankun007/CodeMirror,InternetGuru/CodeMirror,crazy4chrissi/CodeMirror,karevn/CodeMirror,flyskyko/CodeMirror,CartoDB/CodeMirror,wingify/CodeMirror,rrandom/CodeMirror,pabloferz/CodeMirror,tpphu/CodeMirror,d0liver/CodeMirror,jansel/CodeMirror,buchslava/CodeMirror,flyskyko/CodeMirror,dperetti/CodeMirror,Dominator008/CodeMirror,anthonygego/CodeMirror,bgrins/CodeMirror,crazy4chrissi/CodeMirror,vanloswang/CodeMirror,kevinushey/CodeMirror,elisee/CodeMirror,Navaneethsen/CodeMirror,filonb/CodeMirror2,r7kamura/CodeMirror,adobe/CodeMirror2,qweasd1/CodeMirror,mightyguava/CodeMirror,pinbe/CodeMirror,kuangyeheng/CodeMirror,qweasd1/CodeMirror,elisee/CodeMirror,namin/CodeMirror,buchslava/CodeMirror,antimatter15/CodeMirror,ficristo/CodeMirror,ficristo/CodeMirror,hccampos/CodeMirror,systay/CodeMirror,agendor/CodeMirror,loopspace/CodeMirror,ssxxue/CodeMirror,happibum/CodeMirror-main,webida/CodeMirror,adobe/CodeMirror2,Allenice/CodeMirror,ksanaforge/CodeMirror,leafo/CodeMirror2,bluesh55/CodeMirror,GerHobbelt/CodeMirror2,dudb/CodeMirror,michaelerobertsjr/CodeMirror,ficristo/CodeMirror,agendor/CodeMirror,jkaplon/CodeMirror,alur/CodeMirror,shiren/CodeMirror,Ermlab/CodeMirror,trumanliu/CodeMirror,EasonYi/CodeMirror,nawroth/CodeMirror,nightwing/CodeMirror,ejgallego/CodeMirror,thomasjm/CodeMirror,jessegrosjean/CodeMirror,NeZaMy/CodeMirror2,matthewbauer/CodeMirror,morrisonwudi/CodeMirror,xeronith/CodeMirror,jessegrosjean/CodeMirror,cintiamh/CodeMirror,davidpham87/CodeMirror,amshali/CodeMirror,symbla/CodeMirror,morrisonwudi/CodeMirror,ThebingServices/CodeMirror,isdampe/CodeMirror,wingify/CodeMirror,notepadqq/CodeMirror,antimatter15/CodeMirror,leoshine/CodeMirror,AlanWasTaken/codemirror,Carreau/CodeMirror,fpco/codemirror,apatawari/CodeMirror,kuangyeheng/CodeMirror,jayaprabhakar/CodeMirror,SidPresse/CodeMirror,loopspace/CodeMirror