Now more Windows-friendly

- cpu_thread now stops and waits on a pthread condition variable, rather
  than sleep(1)ing and waiting to be pthread_kill()'d. Signals don't
  work well on Windows, apparently.
- fopen() now open binary files with the "b" mode
- the keymap red-black tree no longer casts pointers to ints, because
  mingw/gcc complains about it
- added a dumb batch script to compile the sdl gui on windows
- {n,h}to{h,n}{s,l,ll} is now handled better on windows