Tracbacklog

* The corresponding row in the rank table is now deleted when a ticket is
deleted.

* Implemented a better algorithm for assigning a default rank when tickets have
been deleted.

* Added some checks to detect ranks without tickets and tickets without ranks,
and clean up the tables. These new checks will require you to run a
trac-admin env upgrade.

* Changed queries to use single quotes for better compatibility with
PostgreSQL.

* Updated queries to use the `db.cast()` method for compatibility with MySQL.

* Added the ability to send tickets to the top or bottom via a context menu.
A huge thanks to Brent Atkinson for implementing this feature.

* TICKET_MODIFY is no longer required to view the backlog, only TICKET_VIEW.
Modifying the backlog now requires BACKLOG_MODIFY. Patch by Brent Atkinson.

* Added a preference pane to allow users to customize what they see in the
backlog. Patch by Brent Atkinson.

* Added a Content-Length to the response header, allowing tracd to work
* correctly. Patch by Hiroyuki Wada.

* Fixed the source distribution on Python 2.6.

* Added support for Trac 0.12 and 1.0.

* Fixed a bug where tickets were missing in the unscheduled view after a
milestone was deleted (and the tickets were re-target to None).

* Fixed ticket links when viewing the backlog for a specific milestone.

* Added ticket counts on the milestone targets.

* Fix the backlog page titles to reflect the milestone you're viewing.
* Add more metadata to setup.py.