DEFERRED_SHADING_DEMO: Move debug geometry rendering to its own function
DEFERRED_SHADING_DEMO: Allow debug spheres to be toggled in the settings menu
DEFERRED_SHADING_DEMO: Create a shader for creating scaled and translated quads
DEFERRED_SHADING_DEMO: Create a shader for rendering gbuffers to the screen
DEFERRED_SHADING_DEMO: Render the gbuffer parts to the screen
DEFERRED_SHADING_DEMO: Move these shaders down with the others

Pure organizational change
DEFERRED_SHADING_DEMO: Turn off depth writing for debug objects

So they don't show up in the gbuffers. The objects are solid color, so lack of culling
with itself isn't a problem.
DEFERRED_SHADING_DEMO: Increase the width of the settings menu so as to fit all the item labels
DEFERRED_SHADING_DEMO: Fix the type of the Normal GBuffer.