Added ColorPickerWidget
Renamed cmsplugin_cascade_cascadeelement -> cmsplugin_cascade_element

Otherwise the name of some database tables are too long
Renamed glossary_fields -> partial_fields

because JSONMultiWidget will be used outside Cascade...Plugins
Renamed glossary_fields -> partial_fields

since this widget is getting more generic
Separated div's for glossary_widget and glossary_<fieldname>
Py3 compatible
PartialFormFields can be grouped into fieldsets to render them in the same line
Final model using a JSONField to store all settings for PluginExtraFields