Put the vertex sampler offset firmly at TEXTURE16

Fix memory leak in mtlDeleteShader

C buildfix

Add uniform block support for vulkan

Unused variables

Forgot to commit the new testparse...

Major refactor of the Effects API. The previous API was very GL-specific and had no abstraction at all, meaning new backends had to copypaste WAY too much code just to get started. Additionally, parsing/compiled were separate but still very tightly coupled, to the point where memory leaks in the GL implementation were inevitable. TL;DR: It was crap and nobody liked working with it. The new API provides only a compile function, and moves ALL the effect work to a common implementation. This is done by providing a shader context at compile time, with functions that map almost directly to the existing MojoShader GL API. This is MUCH less work to maintain and add to, to the point where you can see how a parse API is still possible in the updated testparse! It also means new shader backends no longer need to worry about the effects framework so much. The Metal work in this patch was done by Caleb Cornett, as always.

Use __cdecl instead of __stdcall

Skip Gestalt when min version is 10.5+

Buildfixes for CentOS, MinGW, osxcross