Added better detection for content editable for iOS.
Added better detection for content editable for iOS.

fillabs/TinySpecMCE,rbecheras/tinymce,jashua212/tinymce,nbcp/tinymce,gabixdev/tinymce,ikuchmin/tinymce,enfold/tinymce,MediehusetTek/tinymce,shilpi230/tinymce,aduth/tinymce,kencheung/tinymce,Razzwan/tinymce,FernCreek/tinymce,danchr/tinymce,tinymce/tinymce,gabixdev/tinymce,fashionsun/tinymce,henrythewasp/tinymce,nikolas/tinymce,dziemian007/tinymce,dziemian007/tinymce,jashua212/tinymce,ETSI-CTI/TinySpecMCE,jtark/tinymce,Razzwan/tinymce,simachewh/tinymce,adaptiffdesigns/tinymce,tinymce/tinymce,fhchina/tinymce,endjin/tinymce,nikolas/tinymce,pmpl-5/tinymce,M4R7iNP/tinymce,simachewh/tinymce,adaptiffdesigns/tinymce,VioletLife/tinymce,aduth/tinymce,leofeyer/tinymce,sjbufton/tinymce,fhchina/tinymce,danchr/tinymce,rxl194/tinymce,rednose-public/tinymce,henrythewasp/tinymce,TeamupCom/tinymce,1099511627776/tinymce,bsuh/tinymce,M4R7iNP/tinymce,fillabs/TinySpecMCE,danielpunkass/tinymce,kencheung/tinymce,Zimbra/tinymce,danielpunkass/tinymce,howanghk/tinymce,blakewallan/tinymce,support-dot-com/tinymce,pmpl-5/tinymce,gencer/tinymce,Zimbra/tinymce,blakewallan/tinymce,bsuh/tinymce,nbcp/tinymce,rbecheras/tinymce,sjbufton/tinymce,support-dot-com/tinymce,gencer/tinymce,FernCreek/tinymce,endjin/tinymce,jtark/tinymce,rednose-public/tinymce,shilpi230/tinymce,danielpunkass/tinymce,VioletLife/tinymce,tinymce/tinymce,TeamupCom/tinymce,FernCreek/tinymce,rxl194/tinymce,sachgits/tinymce,howanghk/tinymce,ikuchmin/tinymce,1099511627776/tinymce,MediehusetTek/tinymce,leofeyer/tinymce,enfold/tinymce,ETSI-CTI/TinySpecMCE,sachgits/tinymce,fashionsun/tinymce