Add checks for double Filenames.
Property "allowDuplicates: false" prevents to add a file which already exists.
Property "duplicateStrict: true" will check for same filename in lowerCase.
Add hoverClass to dragdropContainer and move a few (not all) classes to configObject (s) for custom layouts.
Fix img-tag-error.
Move hoverClass to configObject (s) for custom layouts.
Merge remote-tracking branch 'origin/master'

Conflicts:
	js/jquery.uploadfile.js