Renderer: Fine-tuned lighting and halo default settings

Dynamic lights are a little larger and glows/halos a little brighter.
Sky color is factored in a bit more into sector lighting.
Client: Read-only setting profiles; added "Retro" and "Enhanced"

Added two built-in renderer appearance profiles that are available
for use in read-only mode.
Merge branch 'master' of github.com:skyjake/Doomsday-Engine

Conflicts:
	doomsday/client/src/ui/editors/rendererappearanceeditor.cpp
Merge branch 'master' of github.com:skyjake/Doomsday-Engine