Add Lua Ultimate Mode global variable so people can use it.

src/dehacked.c

@@ -8217,6 +8217,9 @@ static inline int lib_getenum(lua_State *L)
 	} else if (fastcmp(word,"maptol")) {
 		lua_pushinteger(L, maptol);
 		return 1;
+	} else if (fastcmp(word,"ultimatemode")) {
+		lua_pushboolean(L, ultimatemode != 0);
+		return 1;
 	} else if (fastcmp(word,"mariomode")) {
 		lua_pushboolean(L, mariomode != 0);
 		return 1;