unused defines cleaning / a few fixes for clock

src/window.cpp

@@ -18,6 +18,9 @@
  *   51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.              *
  ***************************************************************************/
 
+#include <cstring>
+#include <cstdlib>
+
 #include "window.h"
 
 using std::string;