Fix monster trapped state being wrong

When cloning a monster, clear the clone trapped and hiding states.
When splitting a monster (eg. a black pudding), the clone could
be placed on a trap, so do mintrap.
When removing a monster from the map, clear the trapped state.

src/uhitm.c

@@ -1227,7 +1227,8 @@ int dieroll;
             /* but not bashing with darts, arrows or ya */
             && !(is_ammo(obj) || is_missile(obj)))
         && hand_to_hand) {
-        if (clone_mon(mon, 0, 0)) {
+        struct monst *mclone;
+        if ((mclone = clone_mon(mon, 0, 0)) != 0) {
             char withwhat[BUFSZ];
 
             withwhat[0] = '\0';
@@ -1235,6 +1236,7 @@ int dieroll;
                 Sprintf(withwhat, " with %s", yname(obj));
             pline("%s divides as you hit it%s!", Monnam(mon), withwhat);
             hittxt = TRUE;
+            mintrap(mclone);
         }
     }