GLMixer Code

Small change in selection behaviour; delete the selection without having to select one of its source, but also discard the selection when a new source is made current.

Implementation of selection operations using SelectionArea for GeometryView.
+ fixed management of non-modifiable sources
+ made selectionSource forward (selected first) by giving it max layer

Implementation of SelectionArea class to perform operations of mouse selection in Mixing and Geometry view (replacement of MixingView selectionRectangle).

Towards action keyboard shortcuts configuration ; created a method to list all actions of GLMixer

Implementation of visual overlay information for tools in Geometry View (center of rotation, proportional scaling diagonals, crop indication)
+ moved computeBoundingBox method (static) to GeometryView

typo

update development status

Implementation of source control actions for menu and toolbar; play/stop (if playable), seek and pause (for media) of ALL SELECTED sources simultaneously.
+ cleanup naming in menu and toolbars
+ various code improvements

Code improvement ; simulate a movement of the mouse on mouse Wheel Event (instead of repeating code)

Made limbo area scalable in the MixerView (mouse action and display of highlighted border)