Have runed doors appear in level annotations.

I'm not 100% happy with how I did this. We just add
a note to the general annotation string. No extra notes
are added for more doors (because runed doors might be multi-cell
and the edge cases there had a chance to get really gross),
and we don't remove the note when the door is opened (for much
the same reasons; and also it might be nice to know the vault
is there even after opening it).
Annotate levels when corrupting them with Lugonu
Minor cleanups.
Don't hardcode the zombie speed modifier.