Add: Callbacks for a room being deactivated (crashed or edited/removed).
Change: "Send to research" choice in faxes can become unavailable again if research department is removed.
Fix: Update buttons on already opened faxes when availability of a choice changes.
Fix: Do not count deactivated (being edited) rooms as available.
Codechange: Allow multiple room build (and remove) callbacks per humanoid.

git-svn-id: http://corsix-th.googlecode.com/svn/trunk@1864 c39591fa-788f-11de-a72b-d90af8dea425