U189 - killing an engulfing monster over water allows waterwalking

- The code in xkilled failed to call spoteffects after killing the monster
that was engulfing you.  Being expelled already worked correctly.
- While testing this, I discovered that removing a ring of levitation or
similar while engulfed would call spoteffects when it shouldn't.  Fixed
that too.

src/mon.c

@@ -1759,8 +1759,9 @@ xkilled(mtmp, dest)
 		redisp = TRUE;
 	}
 #endif
-	if(!accessible(x, y) && !is_pool(x, y)) {
-	    /* might be mimic in wall or corpse in lava */
+	if((!accessible(x, y) && !is_pool(x, y)) ||
+	   (x == u.ux && y == u.uy)) {
+	    /* might be mimic in wall or corpse in lava or on player's spot */
 	    redisp = TRUE;
 	    if(wasinside) spoteffects(TRUE);
 	} else if(x != u.ux || y != u.uy) {

src/trap.c

@@ -2154,6 +2154,11 @@ long hmask, emask;     /* might cancel timeout */
 	HLevitation &= ~hmask;
 	ELevitation &= ~emask;
 	if(Levitation) return(0); /* maybe another ring/potion/boots */
+	if(u.uswallow) {
+	    You("float down, but you are still %s.",
+		is_animal(u.ustuck->data) ? "swallowed" : "engulfed");
+	    return(1);
+	}
 
 	if (Punished && !carried(uball) &&
 	    (is_pool(uball->ox, uball->oy) ||