The code has been imported, tickets have migrated and the Bitbucket repository is now a redirect: the IMAPClient project is now using Git and Github.
The Github link is: https://github.com/mjs/imapclient
(http://imapclient.freshfoo.com redirects to the new location)
This change has been planned for a long time. I've noticed a that many contributors struggle with Mercurial and Bitbucket, and I greatly prefer Git myself nowadays.