VS 2013 build of NetHack.exe and also fix level file locking

include/extern.h

@@ -738,6 +738,7 @@ E void FDECL(free_saved_games, (char**));
 #ifdef SELF_RECOVER
 E boolean NDECL(recover_savefile);
 #endif
+E int FDECL(nhclose, (int));
 #ifdef HOLD_LOCKFILE_OPEN
 E void NDECL(really_close);
 #endif

include/ntconf.h

@@ -99,6 +99,9 @@ extern void FDECL(interject, (int));
 #pragma warning(disable:4996)	/* VC8 deprecation warnings */
 #pragma warning(disable:4142)	/* benign redefinition */
 #pragma warning(disable:4267)	/* conversion from 'size_t' to XX */
+#  if (_MSC_VER > 1600)
+#pragma warning(disable:4459)	/* hide global declaration */
+#  endif /* _MSC_VER > 1600 */
 # endif /* _MSC_VER > 1000 */
 #pragma warning(disable:4761)	/* integral size mismatch in arg; conv supp*/
 # ifdef YYPREFIX