This is a work in progress for adding support for posting comments
to the KNewStuffCore framework, and cleaning up voting a touch. It
further adds UI for creating said comments to KNSQuick.
* Add signals to fake a virtual function for posting a comment
* Implement comment posting (and userCanVote check)
* Add invokable functions for creating comments (and reviews)
* Add voting function to the quickitemsmodel (and userCanVote role)
* Entry details checks for voting ability
* Don't allow voting from the list view (in the old dialog)
* Allow clearing the Rating control when it's editable
* "New Comment" sheet added to the entry comments page
This does not strictly require D25961, but without it this will simply not allow voting and commenting with the attica backend