[markdown mode] Fix irresponsible use of global/static variable
[markdown mode] Fix irresponsible use of global/static variable

Closes #3787

crazy4chrissi/CodeMirror,bfrohs/CodeMirror,INTELOGIE/CodeMirror,hackmdio/CodeMirror,TDaglis/CodeMirror,rrandom/CodeMirror,Dominator008/CodeMirror,bfrohs/CodeMirror,rrandom/CodeMirror,ashmind/CodeMirror,SidPresse/CodeMirror,ficristo/CodeMirror,adobe/CodeMirror2,SidPresse/CodeMirror,adobe/CodeMirror2,namin/CodeMirror,wingify/CodeMirror,Dominator008/CodeMirror,notepadqq/CodeMirror,grzegorzmazur/CodeMirror,kerabromsmu/CodeMirror,InternetGuru/CodeMirror,xeronith/CodeMirror,sourcelair/CodeMirror,codio/CodeMirror,SidPresse/CodeMirror,TDaglis/CodeMirror,crazy4chrissi/CodeMirror,schanzer/CodeMirror,grzegorzmazur/CodeMirror,mizchi/CodeMirror,alur/CodeMirror,hccampos/CodeMirror,codio/CodeMirror,MarcelGerber/CodeMirror,ejgallego/CodeMirror,vincentwoo/CodeMirror,Jisuanke/CodeMirror,ashmind/CodeMirror,mtaran-google/CodeMirror,jayaprabhakar/CodeMirror,vincentwoo/CodeMirror,Dominator008/CodeMirror,alur/CodeMirror,antimatter15/CodeMirror,mtaran-google/CodeMirror,schanzer/CodeMirror,kerabromsmu/CodeMirror,notepadqq/CodeMirror,dperetti/CodeMirror,adobe/CodeMirror2,codio/CodeMirror,ejgallego/CodeMirror,notepadqq/CodeMirror,rrandom/CodeMirror,ficristo/CodeMirror,jkaplon/CodeMirror,wingify/CodeMirror,hccampos/CodeMirror,mizchi/CodeMirror,INTELOGIE/CodeMirror,xeronith/CodeMirror,antimatter15/CodeMirror,mtaran-google/CodeMirror,jkaplon/CodeMirror,MarcelGerber/CodeMirror,hccampos/CodeMirror,pabloferz/CodeMirror,INTELOGIE/CodeMirror,nightwing/CodeMirror,ejgallego/CodeMirror,namin/CodeMirror,Jisuanke/CodeMirror,InternetGuru/CodeMirror,mizchi/CodeMirror,wingify/CodeMirror,sourcelair/CodeMirror,ficristo/CodeMirror,antimatter15/CodeMirror,hackmdio/CodeMirror,xeronith/CodeMirror,bfrohs/CodeMirror,schanzer/CodeMirror,TDaglis/CodeMirror,dperetti/CodeMirror,jayaprabhakar/CodeMirror,grzegorzmazur/CodeMirror,Jisuanke/CodeMirror,thomasjm/CodeMirror,nightwing/CodeMirror,vincentwoo/CodeMirror,hackmdio/CodeMirror,namin/CodeMirror,pabloferz/CodeMirror,nightwing/CodeMirror,jkaplon/CodeMirror,dperetti/CodeMirror,ashmind/CodeMirror,crazy4chrissi/CodeMirror,InternetGuru/CodeMirror,MarcelGerber/CodeMirror,kerabromsmu/CodeMirror,jayaprabhakar/CodeMirror,thomasjm/CodeMirror,alur/CodeMirror,sourcelair/CodeMirror,pabloferz/CodeMirror,thomasjm/CodeMirror