fix more of #2629 - striking/force bolt feedback (trunk only)

From a bug report, the message "Boing!" is given if wand of striking
or spell of force bolt is aimed at magic resistant hero by self or by
monster, or at magic resistant monster by another monster, but it was
omitted when aimed at magic resistant monster by the hero.  The shield
effect animation for resistance is given in all the cases.

doc/fixes35.0

@@ -414,6 +414,7 @@ alchemical explosion or evaporation only used up one potion instead of all
 feedback for reverse-genocide was plural even when just one monster was created
 fix message given when part of a stack of items in a monster's inventory is
 	being destroyed
+add "Boing!" message when hero zaps resistant monster with striking/force bolt
 
 
 Platform- and/or Interface-Specific Fixes

src/zap.c

@@ -171,6 +171,7 @@ struct obj *otmp;
 		reveal_invis = TRUE;
 		if (resists_magm(mtmp)) {	/* match effect on player */
 			shieldeff(mtmp->mx, mtmp->my);
+			pline("Boing!");
 			break;	/* skip makeknown */
 		} else if (u.uswallow || rnd(20) < 10 + find_mac(mtmp)) {
 			dmg = d(2,12);