Cross-platform SDL2 bindings for .NET Core/Standard

This library is an almost 1-to-1 cross-platform wrapper around SDL2, generated from header files.

Why almost? Some function signatures (like the ones accepting char*, etc.) was edited to be a little more ergonomical to use.

Projects using this library

• Imagini - cross-platform .NET Standard game/multimedia app engine - the wrapper was developed for it

Supported platforms

Windows	Linux	OSX
?	✓	?

Note: the library should work under Windows and OSX, because the loading code is mostly identical to the code used in the Veldrid project.

I just need to get my hands on my other testing machines to confirm (if you happen to confirm it before me, it'll be great).