Move vfxcompile headers to Common fodler
Make vfxcompile compile as an importable library
Modify Vfxcompile to be hookable to materialsystem, expand methods to flexibilize how shaders will be compiled, add namespace to shared vfxcompile methods
Add vfxcompile to materialsystem2
Expand shadercompile concommand, hook modified VFXCompile::CompileShaders method to it
Merge branch 'master' of sbox