call urlify only if there is something to urlify
(otherwise, js breaks when URLify is not imported)
Merge branch 'develop' of github.com:divio/django-cms into develop
Merge pull request #1787 from alesdotio/develop

fixes change_form.html breaking text-ckeditor (on plugin creation)
added correct url handling for remove plugin
Merge branch 'develop' of github.com:divio/django-cms into develop
copied plugins can now be deleted