LDEV-4429 Modify bootstrapTabs plugin
The "element.getAscendant"'s function that was specified in Double click
and contextMenu listener methods were replaced with the following:
return !( element instanceof CKEDITOR.dom.document ) &&
element.hasClass('bootstrap-tabs') ;
As otherwise it always false positively determined there is a tabs
element in CKEditor canvas (due to LAMS header containing a tab).
