Remove all WIN32 ifdefs (unifdef -UWIN32)

Just use cygwin.

This looks like it wasn't enough to do anything useful, and I don't
think anyone cares about supporting win32 the hard way.

src/core/misc.c

@@ -430,11 +430,7 @@ int mkpath(const char *path, int mode)
 
 		dir = g_strndup(path, (int) (p-path));
 		if (stat(dir, &statbuf) != 0) {
-#ifndef WIN32
 			if (mkdir(dir, mode) == -1)
-#else
-			if (_mkdir(dir) == -1)
-#endif
 			{
 				g_free(dir);
 				return -1;