Multitouch support with gesture recognition for pan, pitch, tab and tab&hold (#33)
Move touched items to front
Minor tweaks
Weight scale factor for pinch
Fix nan/inf while pinching
Tweak gesture handling
Add doubletap recognizer + handling: 1to1 and fullscreen size
Fix gestures on view, minor fixes and cleanups
Grab tap gesture to bring items to front
Denoise
Merge interaction feature from https://github.com/gregjohnson/DisplayCluster
Fix after merge
Implement #23: Launcher feature using coverflow for directory and supported files, including touch interaction, navigation and item selection
Merge branch 'master' into interaction

Conflicts:
	CMakeLists.txt
	src/ContentWindowGraphicsItem.cpp
Fix stream quit
Tweaks after interaction merge
Fix downstream projects using stream API
Speedup image pyramid generation
Fix 1to1 size for image pyramids
Merge branch 'master' into interaction