This adds a basic freeform ability to mark Plugins as "child_only" and
optionally, who can be its Parents -- should mirror the allow_children /
child_classes functionality.
simplifying get_parent_plugins and centralizing filter logic for parent_classes under get_toolbar_plugin_struct. renamed child_only to require_parent as the wording makes more sense in context of the other PluginBase attributes
some basic tests for require_parent / parent_classes + a stray tab
Merge branch 'develop' of pgithub.com:divio/django-cms into develop
addl updates
aaand now my tests pass for parent/child classes
Merge pull request #2194 from sbussetti/develop

This adds a basic freeform ability to mark Plugins as "child_only" and optionally, who can be its Parents