v0.3.1a: cleaned up quickslot autotargeting:

- quickslots will now only autotarget enemies they can actually auto-aim for.
- cleaned up code for determining which items should use targeting

src/com/shatteredpixel/shatteredpixeldungeon/items/weapon/melee/MagesStaff.java

@@ -61,6 +61,7 @@ public class MagesStaff extends MeleeWeapon {
 		image = ItemSpriteSheet.MAGES_STAFF;
 
 		defaultAction = AC_ZAP;
+		usesTargeting = true;
 
 		unique = true;
 		bones = false;

src/com/shatteredpixel/shatteredpixeldungeon/items/weapon/missiles/MissileWeapon.java

@@ -47,7 +47,9 @@ public class MissileWeapon extends Weapon {
 	{
 		stackable = true;
 		levelKnown = true;
+
 		defaultAction = AC_THROW;
+		usesTargeting = true;
 	}
 	
 	@Override