Massive overhaul of PyGLy.

PyGLy no longer depends on Pyglet.
Examples re-written from ground up.
Examples use single code base to test both legacy and
core profiles.
Examples support single code base to test any platform
provided.
Update to latest Pyrr.
Rename camera.view_matrix to camera.projection_matrix.
Remove view_matrix. You should manually control the
camera's projection_matrix now.
Remove projection_view_matrix.
Remove orthogonal_view_matrix
Remove ratio_viewport.
Fix errors in shader raising an exception and immediately
catching it.
Don't use from OpenGL.GL import *, just import the module
and use the GL prefix for any function calls.
Move gl_legacy.py into gl.py. Legacy functions are marked
as such.
Move gl_utils.py into gl.py.
Rename monkey_patch to pyglet_monkey_patch.
Remove window.py, it is now up to the user to update view
matrices when windows are resized. This was mostly true
before hand, but now we are no longer tied to Pyglet.
Add PyGLFW to contrib directory.
Add all of requirements.txt to requirements-dev.txt for
building documentation on readthedocs.org.
Remove attic directories.