Generic OpenGL Window classes for Qt

* OpenGLWindow creates the OpenGL context and binds it to the window
  surface.
* SimpleOpenGLWindow implements a simple initGL()/resizeGL()/renderGL()
  paradigm.
* TestWindow illustrates the use of SimpleOpenGLWindow.
Improve CMake module for GLM

* Parse version number from setup.hpp
* Document output variables
* Update advanced variables
Upgrade to GLM-0.9.5

GLM-0.9.5 has deprecated the use of degrees in favour of radians. This
is not backwards compatible and therefore the minimum version of 0.9.5
is now required to build.