Dimming of faces based on view-angle.

Subtle fog-like shading for improved distance estimation.
Face-Shading and Fog are now togglable
Anti-Aliased Adaptive Resolution Grid Hotness ( AAARGH ).

Passing actual Camera-Position to Face Shader for improved shading accuracy.
Disabled variable grid thickness for now, re-enable by uncommenting #define USE_Grid_VariableThickness.
Some shader refactoring.
Merge branch 'master' of https://github.com/rebb/TrenchBroom
Cleaned up and disabled fog effect.

Signed-off-by: Kristian Duske <kristian.duske@gmail.com>
Cleaned up and disabled fog effect.

Signed-off-by: Kristian Duske <kristian.duske@gmail.com>

Conflicts:
	Mac/TrenchBroom/TrenchBroom-Info.plist
Merge branch 'refs/heads/Release_1.0.0'