ref #29 remove private path from cmake
ref  #29 rename some _paths to _dirs
Merge branch 'master' of https://github.com/hpicgs/glow.git
fix build
Merge remote-tracking branch 'origin/master' into memory_footprint_11
revisit shader and program, and fix window deinitialization
Merge remote-tracking branch 'origin/master' into memory_footprint_11

Conflicts:
	include/glow/Object.h
	include/glow/Program.h
	source/Program.cpp
	source/Shader.cpp