Fix build with gcc 4.7

[taken from Ubuntu patches]

akode/lib/magic.cpp

@@ -18,6 +18,7 @@
     Boston, MA 02110-1301, USA.
 */
 
+#include <cstring>
 #include "akodelib.h"
 #include "magic.h"
 #include "file.h"

akode/lib/player.cpp

@@ -18,6 +18,8 @@
     Boston, MA 02110-1301, USA.
 */
 
+#include <cstring>
+
 #include <pthread.h>
 #include <semaphore.h>
 #include <assert.h>