Doomsday Engine

Renderer: Respect color tints when drawing sector lighting model "full bright"

Previously when the light amplification visor was collected, all of
the light color effects were disabled. Sector and surface color tints
defined via XG and/or DED and the sky light color were all turned off.

Now the sector lighting model applies the "full bright" modifier to
the ambient light level before multiplying it with the ambient color.