Merge branch 'matthiaskrgr/srgb' into 'master'

Merge branch 'matthiaskrgr/srgb' into 'master'

switch maps to sRGB

Switches all maps to sRGB lighting

had to change light intensity in most cases, added some _sRGB textures (to not break old maps), added script to change all lights on a map, some maps have bounce lighting now.

Maps:

- [x] _hudsetup
- [x] afterslime
- [x] atelier
- [x] catharsis
- [x] dance
- [x] drain
- [x] finalrage
- [x] glowplant
- [x] implosion
- [x] leave_em_behind
- [x] nexballarena
- [x] oilrig
- [x] runningman
- [x] runningmanctf
- [x] solarium
- [x] space-elevator
- [x] stormkeep
- [x] techassault
- [x] vorix
- [x] warfare
- [x] xoylent

See merge request !32