Cleanup (#248)

* Silence some clang warnings

* Cleanup input and turbo functions

* Update apu pulse' swap duty cycle

src/fceu-memory.c

@@ -19,6 +19,7 @@
  */
 
 #include <stdlib.h>
+#include <string.h>
 
 #include "fceu-types.h"
 #include "fceu.h"