Remove useless extern "C"
Add a check to avoid sending sync messages while handling async messages
Remove USE_FRUSTUM_CULLING macro.
Remove BRIGHTPASS_FILTER macro.
Remove USE_GBUFFER macro.
Refactor vertex deformation code.
Consistent alien buy menu colors.
Consistent human buy menu colors.
Let's do the same to build menus.
Rename 'rifle' to 'SMG' in the UI only.
Add mine rate back to builder HUD.

Fixes #452
Small changes to make the default UI use American English spelling. Also, small phrasing tweaks.
Tweak to the resource rate text.
Let's explain spawning choices.
Merge branch 'master' into vertexpack