Fixed mixed tabs/spaces issue in changelog.txt.
Fixed mixed tabs/spaces issue in changelog.txt.

ice8lue/tinymce,Zimbra/tinymce,jtark/tinymce,dziemian007/tinymce,MediehusetTek/tinymce,widgetfactory/tinymce,dziemian007/tinymce,support-dot-com/tinymce,endjin/tinymce,toxalot/tinymce,bsuh/tinymce,gencer/tinymce,VioletLife/tinymce,fillabs/TinySpecMCE,M4R7iNP/tinymce,leofeyer/tinymce,henrythewasp/tinymce,ikuchmin/tinymce,sachgits/tinymce,tinymce/tinymce,widgetfactory/tinymce,Kindling/tinymce,kencheung/tinymce,simachewh/tinymce,danielpunkass/tinymce,toxalot/tinymce,TeamupCom/tinymce,danchr/tinymce,blakewallan/tinymce,fashionsun/tinymce,TeamupCom/tinymce,rbecheras/tinymce,shilpi230/tinymce,Razzwan/tinymce,sachgits/tinymce,Razzwan/tinymce,ChristophKaser/tinymce,endjin/tinymce,ice8lue/tinymce,MediehusetTek/tinymce,adaptiffdesigns/tinymce,sjbufton/tinymce,nikolas/tinymce,pmpl-5/tinymce,danielpunkass/tinymce,collective/tinymce,mplank/tinymce,fillabs/TinySpecMCE,Shopify/tinymce,Zimbra/tinymce,leofeyer/tinymce,aduth/tinymce,enfold/tinymce,fashionsun/tinymce,1099511627776/tinymce,1099511627776/tinymce,howanghk/tinymce,pmpl-5/tinymce,ETSI-CTI/TinySpecMCE,simachewh/tinymce,Kindling/tinymce,ETSI-CTI/TinySpecMCE,fhchina/tinymce,enfold/tinymce,collective/tinymce,FernCreek/tinymce,adaptiffdesigns/tinymce,bsuh/tinymce,howanghk/tinymce,mplank/tinymce,rednose-public/tinymce,nbcp/tinymce,henrythewasp/tinymce,aduth/tinymce,cclaerhout/tinymce,cclaerhout/tinymce,nbcp/tinymce,gabixdev/tinymce,rxl194/tinymce,ChristophKaser/tinymce,rxl194/tinymce,jtark/tinymce,FernCreek/tinymce,kencheung/tinymce,M4R7iNP/tinymce,jashua212/tinymce,tinymce/tinymce,fhchina/tinymce,gencer/tinymce,FernCreek/tinymce,ikuchmin/tinymce,rednose-public/tinymce,sjbufton/tinymce,rbecheras/tinymce,tinymce/tinymce,support-dot-com/tinymce,danielpunkass/tinymce,gabixdev/tinymce,blakewallan/tinymce,nikolas/tinymce,danchr/tinymce,VioletLife/tinymce,jashua212/tinymce,shilpi230/tinymce