"Update skin functionality from the base game" -thecraftianman (GH-2)

- code style consistency
- removed unused vars for cvars that never existed
- slight optimization of loops
- merge settings categories into one
- force tool panel labels to fix colors on apply (to the best of ability)
- fix gear icon not applying to utilities tab

more color fixes, force them

use getupvalues helper for DProperties, prob wont fix most addon conflicts that remove debug.getupvalue but shrug

better fix for DProperties

Fixes for DProperties having a hardcoded background

Some fixes with the skin file. This should fix disabled DMenuOption's being all black.