fix interaction of blendfunc with rtlights
basically, we exclude a number of CUSTOMBLEND blendfuncs from receiving rtlights
the rationale is not that doing this is always correct - it is not in some
cases (e.g. for crazy stuff like GL_ONE GL_SRC_COLOR). The rationale is that
the current behaviour for these is wrong too.
All surfaces that now receive rtlights, receive it correctly.
git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@11326
d7cf8633-e32d-0410-b094-
e92efae38249
::stable-branch::merge=
2e6fc7e2da0e578063b0d6111db0d3012dc44908