added TEXF_CLAMP flag for textures

added TEXF_CLAMP flag for textures
r_shadows 3 mode is under heavy construction
changed pvsframecount stuff to be part of the model structure
new function Mod_BuildTextureVectorsAndNormals added
changed/improved how animating textures work
surface texture chains are now permanent for the lifetime of the model, and are specific to each submodel
surface textures now have a rendertype field which is updated every time R_PrepareSurfaces is called, values are SURFRENDER_ADD, SURFRENDER_ALPHA, or SURFRENDER_OPAQUE
added SHADERSTAGE_BASELIGHTING
added surfaceneighbors system (currently disabled because it increases load time greatly)
surface meshs are now allocated by a single function to simplify things
more heavy construction on static shadow volumes (which aren't working correctly)
VectorNormalize, VectorNormalize2, and VectorNormalizeDouble macros no longer produce infinite vectors if given null vectors
corrected names of dot3 enums
reduced duplicate code in texture manager with some new arrays for gl texture type enums
added GL_SetupView_Mode_PerspectiveInfiniteFarClip based on code from tenebrae
texture state management now has combinergb and combinealpha for each texture unit
aliasvert array went away
aliasvert_svectors, aliasvert_tvectors, and aliasvert_normals added (note: padded to 4 floats)
aliasvertnorm replaced with aliasvert_normals (adjusted code to use 4 float padding)
new r_light_* cvars allow tweaking of r_shadows 3 lighting system
R_DrawShadowSphere now works correctly
fixed fakeshadows appearing ontop of transparent stuff
got rid of unused RSurfShader_Wall_Fullbright

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@2522 d7cf8633-e32d-0410-b094-e92efae38249