Use Configurable Options for cl.exe calls.

[orcmid]

The cl.exe calls will rely on @-includes for certain variability. These should be modifiable by users and in a .gitignore that keeps the expanded build-point ignored in the rayLab and raylib clones, but potentially backed up in a repo of the user' choosing.

This leads to some interesting cases on nfoTools, where raylib might appear in the Toolcraft.

Options should apply to includes, compiling, and linking. The options should be dependencies with regard to any Make usage.

My intention is that build should be for releases. I would like to not distinguish via Release/ and Debug/ but just a flat build. There needs to be a way to have Release/ and Debug/ for those who want to mirror the Visual Studio practice.

I think using CMake, a build generator, is too much for a basic drop-in. It should not be prevented. It is just a bridge too far for starters and simple work. Yet scaling to it should be possible/straight-forward. Also, my focus on building on Windows for Windows means that porting farther is maybe not an option. So then there is consideration of build options with respect to raylib dependencies.