Minor change to wands, staves, and scrolls

You should now be able to use wands, scrolls, and staves like "normal"
spells with respect to their targets.

For example, that means that a scroll with fireball can be used as
"recite scroll" to hit your current victim, and a wand of bless can be
used on objects, etc.

I don't think any backwards-incompatible changes were made, but please
look out for bugs.

- Dain