DX 12 learning stuff

Only thing useful for somebody else right now is stuff in common library file. With that common library I've started a painful journey to convert Microsoft's d3dx12.h to Rust.

Everything considered written by me is licensed with MIT, some bits of the code is from other tutorials I have yet to document. Since most tutorials are written in C++, the code isn't pasted anywhere, I have translated relevant parts.

Tutorials and materials used for the samples:

• Microsoft's DirectX 12 Samples
• Introduction to 3D Game Programming with DirectX 12
• Sample codes of Introduction to 3D Game Programming with DirectX 12
• Braynzar Soft