tcGen environment generates texcoords in range of 0.0 to 1.0 and they
need to be offset to the position/size in the merged lightmap atlas.
This also needs to be after tcMods so they apply for the original range.
This fixes tcMod scale used by main_q3abanner and shinygrate1_4.
This issue was visible on the blue monitor (comp3c) near the plasmagun
in q3dm0 and the Quake III Arena banner in q3dm17.
Affected shaders in Quake 3 and Team Arena maps:
textures/base_wall/comp3
textures/base_wall/comp3b
textures/base_wall/comp3b_dark
textures/base_wall/comp3c
textures/base_wall/main_q3abanner
textures/base_wall/shinygrate1_4
textures/sfx/teslacoil
All of the shaders are used by q3dm0 but other maps also use some.
e3abcffeb0