Added keyboard support for slider
Added keyboard support for slider

tinymce/tinymce,nbcp/tinymce,ikuchmin/tinymce,blakewallan/tinymce,henrythewasp/tinymce,adaptiffdesigns/tinymce,TeamupCom/tinymce,ETSI-CTI/TinySpecMCE,TeamupCom/tinymce,gencer/tinymce,leofeyer/tinymce,sjbufton/tinymce,FernCreek/tinymce,FernCreek/tinymce,fillabs/TinySpecMCE,aduth/tinymce,danielpunkass/tinymce,rbecheras/tinymce,fillabs/TinySpecMCE,MediehusetTek/tinymce,leofeyer/tinymce,danielpunkass/tinymce,jtark/tinymce,danielpunkass/tinymce,nbcp/tinymce,ETSI-CTI/TinySpecMCE,FernCreek/tinymce,aduth/tinymce,gencer/tinymce,adaptiffdesigns/tinymce,rbecheras/tinymce,blakewallan/tinymce,MediehusetTek/tinymce,ikuchmin/tinymce,tinymce/tinymce,sjbufton/tinymce,tinymce/tinymce,henrythewasp/tinymce,jtark/tinymce