added GLSL shader path for normal rendering stage, reworked a lot of things to do...

added GLSL shader path for normal rendering stage, reworked a lot of things to do this
removed .lights file loading and the corresponding directional model shading (these were only produced by hlight for q1bsp, very rare files) so that the GLSL normal rendering stage would not have to deal with .lights files
changed R_CompleteLightPoint to properly match rtlight shading, not the old dlights, this allowed removal of the old lightmap_* rtlight fields

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@6128 d7cf8633-e32d-0410-b094-e92efae38249