Store the maximum player file tries in a constant

src/constants.h

@@ -89,6 +89,11 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 // Maximum hit points of a player
 #define PLAYER_MAX_HP 20
 
+// Number of different files to try to save a player to if the first fails
+// (because of a case-insensitive filesystem)
+// TODO: Use case-insensitive player names instead of this hack.
+#define PLAYER_FILE_ALTERNATE_TRIES 1000
+
 /*
  *    GUI related things
  */