Add support for GL_ATI_fragment_shader, new packets R200_EMIT_PP_AFS_0/1,

    R200_EMIT_PP_TXCTLALL_0-5 (replaces R200_EMIT_PP_TXFILTER_0-5, 2 more
    regs) and R200_EMIT_ATF_TFACTOR (replaces R200_EMIT_TFACTOR_0 (8 consts
    instead of 6)