Updates to support OS X. This improves support for building on

multiple systems with automake, with X Windows and Carbon window
system APIs supported.  It's also a starting port for supporting
win32 builds using mingw.  OS X support is incomplete;  the tree
will compile and link but the binaries will not function.

lib/arch/vsnprintf.cpp

@@ -28,7 +28,7 @@ ARCH_STRING::vsnprintf(char* str, int size, const char* fmt, va_list ap)
 	return n;
 }
 
-#elif UNIX_LIKE // !HAVE_VSNPRINTF
+#elif SYSAPI_UNIX // !HAVE_VSNPRINTF
 
 #include <stdio.h>
 
@@ -54,7 +54,7 @@ ARCH_STRING::vsnprintf(char* str, int size, const char* fmt, va_list ap)
 	}
 }
 
-#else // !HAVE_VSNPRINTF && !UNIX_LIKE
+#else // !HAVE_VSNPRINTF && !SYSAPI_UNIX
 
 #error vsnprintf not implemented