Blender Git Loki

Color Management: fixed color management-less texture rendering

There was a missing check for whether color management enabled or not when
converting byte textures to linear space.

This commit also fixes wrong texture preview rendering, which was applying
sRGB transform twice, making procedural textures bright. This will make
float textures being previewed dark (in a linear space) but that's how it
used to behave in pre-OCIO color management.