Remove pointless defines.
Revert "Merge branch 'feature/custom-materials' into develop"

This reverts commit eceb4f2a9fea62fb434c7f999aac936f77f1e403, reversing
changes made to 6de8a9ade054490abf18b6232a1ccd55896d7c0d.

Conflicts:
	src/modules/custommaterials.cpp
Add in custom textures module, which is less likely to crash given that it's not hooking anything.
Change console commands.
Update docs to replace custom materials with custom textures module.
Merge branch 'feature/custom-textures' into develop
Add SetPos hooks.
Add GetClass function.
Add and link up SpecGUIOrder module.
Merge branch 'feature/specguiorder' into develop
Use GetClass in loadout icons.
Update README.
Bump version.
Merge branch 'release/0.19.1' into develop