Tilted ripple

See merge request !524

OpenGL fixes

See merge request !519

Stop characters from being able to activate their abilities when doing a shield ability!

See merge request !522

Restore portal culling code that went gone by pure accident

See merge request !523

Optimize Software drawers

See merge request !533

Rework G_SetCustomExitVars to allow skipstats 2

See merge request !534

Make Amy only hug players at the same Z height

See merge request !521

Add TC_DASHMODE color shader

See merge request !526

Fix Ploadflat closing the game with "Too many flats in level" error message

See merge request !529

Co-authored-by: TehRealSalt <tehrealsalt@gmail.com>