Various improvements & Cleanups

Some ported from ANightly's work

src/floppy/fdd_pcjs.c

@@ -20,7 +20,11 @@
 #include <string.h>
 #include <stdlib.h>
 #include <wchar.h>
+#ifndef _MSC_VER
 #include <unistd.h>
+#else
+#include <io.h>
+#endif
 #define HAVE_STDARG_H
 #include <86box/86box.h>
 #include <86box/timer.h>