Merge pull request #97 from d-j-a-y/master

BugFix #84  -  Select TimeTrack row and press enter crash
Fix bug #543
http://www.synfig.org/issues/thebuggenie/synfig/issues/543
Keyframe synchronization + Selected kf ui + NewKeyframe Crash patch
synchro of selected keyframe between dock & timeline.
part of : http://www.synfig.org/issues/thebuggenie/synfig/issues/458
+
selected keyframe user interface distinction (see forum http://www.synfig.org/forums/viewtopic.php?f=14&t=2962#p20246)
+
newkeyframe crash patch : get_window test (see forum http://www.synfig.org/forums/viewtopic.php?f=15&t=4305#p20278 )
Keyframe synchro - deadloop progress :
has_focus() test on  KeyframeTree::on_selection_changed()
+
selected_kf = keyframe; before signal emission
+
some debug message
Keyframe synchro - deadloop progress 2

No more on_selection_changed signal
Welcome to on_cursor_changed signal
+
More debug message

Deadloop happen when playing a while moving kf first to last between keyframe tree and keyframe widget
Deadloop : unless loop selection of existing keyframe to segfault
Keyframe synchro - deadloop progress - resolving...

- Add select_function connected on get_selection->set_select_function.
(Keyframetree::select_function just only true)

- More debug messages

- Comment message emmission from on_cursor_changed

- keyframetree::on_keyframe_changed , add condition and send_selection

- keyframetree::event Add send_selection on KEY_PRESS message

- Widgetkf::set_select , more conditions
Keyframe synchro

- Keyframes are now synchronized and it's just User Interface, no new functionnality ;-)
When you select a keyframe from the time track, the corresponding keyframe in
the treeview panel will be selected and reverse.

- Developing, a deadloop issue occured sometime moving a keyframe from/to extreme position
and should be resolved. Please, play a little with this feature to verify it's robust enough.

- Sometime, when re-ordering (moving a kf in the kf widget on the time track)
the keyframe treeview get in wired sort mode and that put in trouble the
kf synchro. You need to re order the kf treeview by the time colomn to arrange this
problem.
related issue : http://www.synfig.org/issues/thebuggenie/synfig/issues/481

- Due to focus issues, the first mouse click is not catched.
Keyframe synchro - Add test of signal emitter (progress)
Keyframe synchro - Add test of signal emitter

- add emitter/recipient test based on "this" pointer
- fix "first keyframe panel click not catched" issue