Declare use of OpenGL 3.2 on OS X
Use GLSL version 150 as proposed by vlj
Ignore files added by OS X
Use explicit output value in normalmap fragment
Revert "Use explicit output value in normalmap fragment"

This reverts commit 596495a5dea020141c4c9ed840407c559e03f862.
Bump shader version to 150
Use Log::error rather than log::fatal for non compiling shaders.