Fix close dialog +  add assert
getNodesEntitledForOverlays: small bug fix
+ Tracker: allow multi-threaded tracks
+ getImageFromCacheAndConvert: do not convert if image doesn’t have
good components, instead throw it away (it has nothing to do in the
cache) and convert once render is done.
Overlays are now refreshed only once while in analysis so that the
tracks appear really where they are
Redraw overlays when undoing a Add track op.
Fix compil + update changelog
Fix tarvis
When editing tracks points from the panel, use setValueAtTime
Fix misusage of Thread storage
Small bug fix
Bug fix
Text knob: edit on editing finished only
Don’t update slaves on timeline change
DiskCache fix a small bug with frame range
When getting an image from cache: use its RoD instead of the result of
getRegionOfDefinition
Make sure autosaves are not running when quitting the application.
Knob: allow evaluateValueChange to run in another thread but don’t call
evaluate in that case.
Fix a few bugs where the image cached was not always what was output by
the node but what was requested.
Merge branch 'workshop' into python

Conflicts:
	Engine/Knob.cpp
	Engine/Knob.h
	Engine/KnobImpl.h
Bug fix in hierarchy of groups