Fixed GLEW include path variable in CMakeLists.txt

The CMakeModules/FindGLEW.cmake script was using GLEW_INCLUDE_PATH and
CMakeLists.txt was using GLEW_INCLUDE_DIR, which could not work correctly.
Added self to contributor list
Merge pull request #37 from msiedlarek/master

Fixed GLEW include path variable in CMakeLists.txt