Bug fix: When using color-picker give a reason of USER_EDITED
OfxEffectInstance bug fix: paramInstanceChangedAction() was called twice when parameter was set by plugin
Fix deadlock when closing project
Add a new value changed reason and comment the 3 main value change
reasons:

USER_EDITED = 0,     //< a user change triggered the call, gui will not
be refreshed but instanceChangedAction called
    PLUGIN_EDITED ,     //< a plugin change triggered the call, gui
will be refreshed but instanceChangedAction not called
    NATRON_EDITED, //<  Natron called setValue itself,
instanceChangedAction will be called AND gui refreshed
Picker rectangle: allow to redraw rectangle even if it is already set
NATRON_EDITED is in fact kOfxChangeUserEdited !
Buttons above the property bin are no longer scrolling with the
properties
Merge branch 'workshop' into python

Conflicts:
	Global/GitVersion.h