Remove documentation for external modules.

We don't need these and they clutter up the repository.
Merge pull request #73 from yuriks/remove-docs

Remove documentation for external modules.
Fix wrong threaded usage of OpenGL context.

This fixes crashes on all platform when rendering to the screen.
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.