mash-light-box: Generate the shader before paint
mash-light-box: Generate the shader before paint

MashLightBox now overrides the paint method and generates the
shader. The generate_shader method is called on any lights that are
children of the box so they can affect the shader. The update_uniforms
method is also called on all of the lights.

clutter-project/mash,clutter-project/mash,eliasbakken/mash,eliasbakken/mash,clutter-project/mash