Monsters can see player resistances

If monsters see you resist something, generally elemental or magical
attack, or if they see you reflect an attack, they learn that and
will adjust their attack accordingly.

Originally from SporkHack, but this version comes via EvilHack with
some minor changes.

src/pray.c

@@ -597,9 +597,11 @@ god_zaps_you(aligntyp resp_god)
                 pline("For some reason you're unaffected.");
             else
                 (void) ureflects("%s reflects from your %s.", "It");
+            monstseesu(M_SEEN_REFL);
         } else if (Shock_resistance) {
             shieldeff(u.ux, u.uy);
             pline("It seems not to affect you.");
+            monstseesu(M_SEEN_ELEC);
         } else
             fry_by_god(resp_god, FALSE);
     }
@@ -635,6 +637,7 @@ god_zaps_you(aligntyp resp_god)
         } else {
             You("bask in its %s glow for a minute...", NH_BLACK);
             godvoice(resp_god, "I believe it not!");
+            monstseesu(M_SEEN_DISINT);
         }
         if (Is_astralevel(&u.uz) || Is_sanctum(&u.uz)) {
             /* one more try for high altars */