Fix - Possible hitting something around Toolbox = segfault!
Keyboard event dispatch , test focused_widget != NULL before use it.
Fix : Segfault occurs when changing time of keyframe with new_index 0
Test if current keyframe is not first one (index 0) before search for preivous kf
+
Add explicit catch exception message in case of kf_list->find_prev throw.
Merge pull request #41 from d-j-a-y/master

Fix kb evnt dispatch in Toolbox + Segault on changing first kf time