Make server check game state file sizes on startup

Certain tables have a fixed size depending on configuration: EF_SECTOR
has WORLD_SZ() elements, EF_NATION, EF_MAP and EF_BMAP have MAXNOC
elements, and EF_REALM has MAXNOC * MAXNOR elements.  Bad things
happen if the files backing them are shorter.

Pass expected size to ef_open(), and make it fail when the actual size
differs.

src/util/files.c

@@ -131,7 +131,7 @@ main(int argc, char *argv[])
     for (i = 0; i < EF_MAX; i++) {
 	if (!EF_IS_GAME_STATE(i))
 	    continue;
-	if (!ef_open(i, EFF_CREATE)) {
+	if (!ef_open(i, EFF_CREATE, -1)) {
 	    perror("ef_open");
 	    exit(1);
 	}