Replaced method get_html_attributes by class member `glossary_attributes`
Plugin must offer property `name` otherwise Link is not displayed in CKEditor
Renamed TextLinkPlugin -> LinkPlugin to make it usable by CKEditor as LinkPlugin
Renamed text -> title, since that what it is
Use glossary_attributes to configute property html_attributes
FilerImagePlugin has been replaced by CascadeImagePlugin
Fixed empty field issue for Select2 input fields
Beautified the code
Simplified the code
Adopted templates to new LinkPlugin attr naming
CKEditor uses marked text for link content