Remove documentation for external modules.

We don't need these and they clutter up the repository.
Update CMakeLists to support buliding on Windows.

 - Remove support for Qt4.
 - Update in-tree GLFW binaries to GLFW 3.0.4, both Win32 and Win64
   versions.
 - Remove GLEW. Replace it with a glLoadGen-generated loader for OpenGL
   3.2. This removes one set of precompiled binaries from the tree.
Avoid LOGGING redefinition warnings.
Actually pass QGLFormat to QGLWidget

GGLWidgetInternal wasn't passing the format it received to the parent
constructor, meaning the format wasn't used at all. This make the Qt UI
properly initialize a 3.2 context.
Downgrade required OpenGL version to 3.0