Don't wash out HDR vertex lite surfaces in OpenGL2

Vertex lite surfaces being brighter than light maps looks bad,
they're meant to look the same. Especially in ET, which mixes
them fequently. It's noticeable in Q3 too though.

BSP lightmaps (i.e. not external HDR lightmaps) use
R_ColorShiftLightingBytes, now *Floats (used by vertex colors)
has the same behavior.

This may be a problem for HDR lightmaps, as the RGB will always be
scaled to 0.0 to 1.0 range.

I had enabled this for non-HDR before, but now HDR needs it too.
spearmint: Use correct fog volume for RT_POLY_LOCAL

When looking for fog volume need to add entity origin
to RT_POLY_LOCAL vertices. Before it was checking at map
origin.

This caused sprite issues on q3tourney2 in OpenGL2
(because game code renders sprites using RT_POLY_LOCAL).
Merge remote-tracking branch 'ioquake3/master'