Feature: "Send to research department" option in faxes become available when you build a research room meanwhile. Fixes issue 480.
Fix: When an unanswered fax became meaningless (if you built the required room), it was only removed if its message button was there at the bottom panel (not if it was queued because of 5 buttons being there already)

git-svn-id: http://corsix-th.googlecode.com/svn/trunk@1863 c39591fa-788f-11de-a72b-d90af8dea425