start working on a new rendering pipeline
more integration of new rendering loop
more update to render thread
more rendering thread implementation
add real workhorse for rendering
add a file exist check
cleanup compilation
test updating progress dialog from video writer
cleanup some code
try to correctly update progress
add a callback to prograss task
correclty update progress dialog
correct bug in saving project
update progress on ffmpeg export
some more pragma
Merge remote-tracking branch 'origin/rendertask' into rendertask

Conflicts:
	src/slowmoVideo/lib/ffmpeg_writer.cpp
Merge remote-tracking branch 'origin/rendertask'
add more progress info from ffmpeg

Conflicts:
	src/slowmoVideo/lib/ffmpeg_writer.cpp
	src/slowmoVideo/lib/ffmpeg_writer.h
	src/slowmoVideo/lib/qtkit.h
	src/slowmoVideo/lib/qtkit.mm
	src/slowmoVideo/lib/video_enc.cpp
	src/slowmoVideo/lib/video_enc.h
	src/slowmoVideo/project/exportVideoRenderTarget.cpp