bundle the display-related hints, that tell bot() and others

that an update is required, into a struct. Remove it from
context since there is no reason to save those.

src/minion.c

@@ -377,7 +377,7 @@ bribe(struct monst *mtmp)
         You("give %s %ld %s.", mon_nam(mtmp), offer, currency(offer));
     }
     (void) money2mon(mtmp, offer);
-    gc.context.botl = 1;
+    display.botl = 1;
     return offer;
 }