Investigate strange undo/rewind behavior

[NathanWolf]

Blocks that are automatically added to a block list during an undo action (to protect attached items such as torches, for instance) need to be specially marked.

When a spell like transmute requests an undo list, it shouldn't get these blocks.

Right now, transmute has some strange behavior because of this- though I now have a lovely glass-filled crater because of it.

[NathanWolf]

I need to think more about this- there are definitely some strange behaviors with recall, but the more I use it, the more I actually appreciate being able to point at a home I made and rewind it, since it will hit one of the auto-protected outer blocks and detect the modification (normally you couldn't rewind a destruction spell directly, since there's nothing to target!)