Move shaders from ARB assembly to GLSL

-Removed r_arg_programs.c
-Removed enumeration of ARB_fragment_program and ARB_vertex_program
-Deprecated r_pixel_shader_warp and r_caustics
-Removed warp shaders and caustics options video menu
-Added GLSL warp shader to r_shaderobjects.c
-Added unified r_waterquality cvar
-r_waterquality of 0 is stock Quake 2 water warping
-r_waterquality of 1 uses shaders to perturb water texture
-r_waterquality of 2 uses shaders to draw caustics
-Added water quality option (low/medium/high) to video menu