Follow up on disturbing buried zombies

Change 852f8e4 by requiring a minimum impact before a buried zombie
nearby will be disturbed: light, but still excluding things like
scrolls, if it's a violent impact (dropped while levitating, thrown, or
kicked), and fairly heavy if the hero is just placing the item on the
ground normally.

Moving the call out of flooreffects meant it no longer applied to
pushing boulders around, so have moverock disturb nearby zombies.  I
additionally had wake_nearby do the same thing.

Finally, I renamed check_buried_zombies (which doesn't really reflect
what it does) to disturb_buried_zombies.

src/hack.c

@@ -291,6 +291,15 @@ moverock(void)
                 goto cannot_push;
             }
 
+            if (closed_door(rx, ry))
+                goto nopushmsg;
+
+            /* at this point the boulder should be able to move (though
+               potentially into something like a trap, pool, or lava) */
+
+            /* rumbling disturbs buried zombies */
+            disturb_buried_zombies(sx, sy);
+
             if (ttmp) {
                 int newlev = 0; /* lint suppression */
                 d_level dest;
@@ -401,8 +410,6 @@ moverock(void)
                 }
             }
 
-            if (closed_door(rx, ry))
-                goto nopushmsg;
             if (boulder_hits_pool(otmp, rx, ry, TRUE))
                 continue;
 
@@ -1592,9 +1599,20 @@ u_rooted(void)
     return FALSE;
 }
 
+/* maybe disturb buried zombies when an object is dropped or thrown nearby */
+void
+impact_disturbs_zombies(struct obj *obj, boolean violent)
+{
+    /* if object won't make a noticeable impact, let buried zombies rest */
+    if (obj->owt < (violent ? 10 : 100) || is_flimsy(obj))
+        return;
+
+    disturb_buried_zombies(obj->ox, obj->oy);
+}
+
 /* reduce zombification timeout of buried zombies around px, py */
 void
-check_buried_zombies(coordxy x, coordxy y)
+disturb_buried_zombies(coordxy x, coordxy y)
 {
     struct obj *otmp;
     long t;
@@ -2601,7 +2619,7 @@ domove_core(void)
     }
 
     if (!Levitation && !Flying && !Stealth)
-        check_buried_zombies(u.ux, u.uy);
+        disturb_buried_zombies(u.ux, u.uy);
 
     if (hides_under(gy.youmonst.data) || gy.youmonst.data->mlet == S_EEL
         || u.dx || u.dy)