Fix colormap textures not being updated for palette shaders

src/hardware/hw_cache.c

src/hardware/hw_drv.h

src/hardware/hw_glob.h

src/hardware/r_opengl/r_opengl.c

src/lua_colorlib.c

src/r_data.c

src/r_data.h

src/r_defs.h

src/sdl/hwsym_sdl.c

src/sdl/i_video.c

src/z_zone.c

src/z_zone.h