Bug fix in the knobs gui initialization. When the knob was secret by default and belong to a group it didn't hide.
Bug fix: take into account the new line info when unfolding a group
Fixed the algorithm for creating settings layout of knobs. It now works even with nested groups
Merge branch 'workshop' of https://github.com/MrKepzie/Natron into workshop

Conflicts:
	Global/GitVersion.h