Remove warnings

* Remove assigned but not used variables (GCC 4.6)
* Bump _XOPEN_SOURCE to 600, ridding of FreeBSD warnings (this probably need
  to be tweaked on a per-implementation basis as problems arise)

src/winspector.c

@@ -27,6 +27,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
+#include <strings.h>
 
 #include "WindowMaker.h"
 #include "screen.h"