[ #22324 ] Restore support for double click
[ #22324 ] Restore support for dropping history/contacts/bookmarks into callview
[ #22324 ] Re-implement the drop overlay.

It was implemented twice, once using proxy style and the other by implementing drag{Enter,Leave,Move} methods.
Both implementations are buggy. For now, it use the later one. In the future, the former is probably less tricky
to get "right".
[ #22324 ] Improve drag and drop. This is now on hold until callmodel is ported away from the template
[ #22928 ] Port CallModel to abstractitemmodel (1/6)
[ #22928 ] Port CallModel to abstractitemmodel (2/6)

This one restore the timer and improve the layout
[ #22928 ] Port CallModel to abstractitemmodel (3/6)

* Restore on canvas toolbar and tips.
* Merge historymodel and call ::data() methods
* Complete conference delegate to match the previous look
[ #22321 ] Clean CallModel API, first step toward API 2.0.0

* Also make CallModel stay symatric when the daemon make changes
[ #22321 ] Make CallModel compliant with SFLPhone KDE coding standards
[ #22928 ] Port CallModel to abstractitemmodel (4/6)

This fix:
* Toolbar overlay buttons depending on call state
* Delegate appearance for calls
* Some on canvas tip rendering and position
* Double click on call
* The text event filter for calls
[ #22928 ] Port CallModel to abstractitemmodel (5/6)

* Add call item overlay
* Fix display
* Implement some drag and drop operations
[ #22928 ] Port CallModel to abstractitemmodel (5.5/6)

* Fix delegate drag and drop (mostly)
* Introduce new drop on empty space animation
* Improve some delegates
* Fix events problem
* Fix race condition with multiple clients
[ #22928 ] Port CallModel to abstractitemmodel (6/6)

* Support parametric drag and drop (using qproperties)
* Fix bugs
* Implement conference logic

It is important to note that the daemon will need to be fixed for this to work fine. I prefer to avoir implementing the hacks that made the old version "bug free". There is also a few bugs left. I am leaving this for the polishing iteration later on.
[ #24595 ] Enable all GCC extra warnings and fix them (But effc++ and reorder)
[ #24595 ] Port most enums to C++11 enum classes. This make the code more robust to accidental integer casting
[ #24595 ] Enable more warning in CMakeLists
[ #22322 ] Make automatic selection work again
[ #22322 ] Add a little ringing phone icon for incoming calls when there is multiple active calls
[ #20251 ] Add DISABLE_UNIQUE_APPLICATION compile time option to disable the creation of the background process
[ #22322 ] Fix scaled status icon when no contact images