Characters now check and enable their AI if not in their alcove.

Should fix #53.
Extra precaution against leaving the curtain closed.
Speed up LoadCharacter during upkeep.
Alcove swapping is much more stable, less likely to get stuck lit.

Alcoves can now also be moved while the character is summoned without snatching them back from Tamriel.
Load appearance data before updating perks, shouts, etc.