Copyright-holder and year information is extracted from git log.
git history begins in 2005. So (C) from 1998..2005 is lost. Also some
(C) assignment of commits where the committer didn't use --author.
Sometimes the interthread process window dialog reports "cancelled"
when it was not actually cancelled, it was just hidden and reshown,
Since we are polling the cancel state interthread, we must reset
the cancel status BEFORE the dialog is shown, and never toggle the
cancel state unless it is a true cancel action by the user.
* pressing Esc or WM close button did not cancel import thread
* proper Abort does not wait for import thread either
It was possible to launch a 2nd (and Nth) import thread, all sharing
the Editor's ImportStatus data-structure, all having the same
registered thread-name and same thread-pool name. Plenty of room for
crashes.