Doesn't compile on windows

[jnterry]

The engine does not compile on windows.

Think the only issue is that thpool is linux only - but there might be other problems after that is fixed.

[jnterry]

Work queue implementation depends on a ring buffer type: #7

[jnterry]

There are now many more issues on windows - we probably want to solidify the kernel interface first (in long run that will handle thread management replacing thpool library which is linux only)

[jnterry]

thpool library has been replaced with our own implementation of threads as of: 8ba2dee

Note that our implementation is also linux only, but at least now its only our own code that needs to be ported to get Xeno Engine compiling on windows once more...

[jnterry]

Compiles and runs as of: 681712c

But, some examples crash...

• OpenGL renderer crashes on windows
• software rasterizer works with some examples, but others crash