Removes old "compiled display list" members from Materials.

We haven't compiled display lists in years.  Let's get rid of this
ancient code.
Adds ability to set up to four textures on a material.

(Not yet a way to set texture coordinates for so many textures, but you
can access them from a shader if you like)
Print maximum number of vertex texture units during startup.

(Moves the check from vsRenderSchemeBloom to vsRenderer)