Tweaks to Scroll of Infinite spells

Better messages.

'r' the book to learn the spell.

'#invoke' the book to cast the spell.
If the Scroll is given as a crowning gift, the initial spell if FoD

If no book can be given, FoD is added to the Necronomicon in your open inventory.

If no Necronomicon is in your open inventory, the spell of the Scroll becomes Finger of Death.