Disallow duplicating gmod_hands
* There's a save on workshop that somehow has 7000 of the things, which I don't expect to be intentional.
Minor changes to overlay rendering from CS:GO
Batched overlay rendering support
Merge normal calc for overlay stuff from CS:GO
Static prop physics scaling
Fix some air being considered water on CSGO dangerzone maps
* It was partially fixed for grenade clips, now fixed for drone clips
r_staticpropinfo 5 shows static prop bounds
* Just for debugging
Unhide r_renderoverlaybatch for now