pthreads-win32

pthreads-win32 was starting to get a little annoying, so I decided to stop using it as a dependancy. I wrote a native win32 implementation of the threads in GNE now so pthreads-win32 is not needed.

HawkNL uses pthreads-win32 by default though, so compile HawkNL with NL_WIN_THREADS enabled. I will be providing a binary (MSVC) distribution of HawkNL with GNE in the future releases with permission of the author.

This binary version will differ in that NL_WIN_THREADS is true, and the library is compiled such that the MSVC runtime is dynamically linked to decrease the size of the HawkNL DLL (with /MT rather than /ML)