eels in lava

<Someone> reported that randomly placed aquatic monsters can end up in
lava.  The placement code allowed lava whenever the WET flag was passed to
it.  This was so passing (WET|DRY) would match all locations, but it's not
appropriate for when only the flag WET is used.  Since we have no levels
currently affected by this bug, I fixed it only in the trunk.

src/sp_lev.c

@@ -222,7 +222,7 @@ register int humidity;
 		return TRUE;
 	}
 	if (humidity & WET) {
-	    if (is_pool(x,y) || is_lava(x,y))
+	    if (is_pool(x,y) || ((humidity & DRY) && is_lava(x,y)))
 		return TRUE;
 	}
 	return FALSE;