NEW: equalizer window hiding code
NEW: event dispatch enable / disable and (WIP) tile show / hide commands
Merge branch 'master' into endurance-hacks

Conflicts:
	src/omega/Engine.cpp
switched version to v4.1-alpha3
endurance hacks
Merge branch 'endurance-hacks' of https://github.com/febret/omegalib into endurance-hacks
CHANGE: some customizations to button and image widget, to display an button image even when no pixel data is attached to it. Used in endurance demo to draw custom colored box in buttons
NEW: tile visibility control implemented in Equalizer classes.
NEW: point cloud binary loader batch support
CHANGE: added culling to binary points loader
FIX: timing in OsgRenderPass.cpp