Merge pull request #22 from tribal-tec/master

Fix GL feature detection for hwloc
Fix GLEW_MX finder
Fix GLEW_MX finder
Add glxewContextInit needed on OS X since MacPorts GLEXMx does not cover GLX
Merge branch 'master' of https://github.com/Eyescale/CMake
Add IGNORE_LIB_TARGETS to not be added to PROJECT_LIBRARIES list