Requested by Steve Bellovin in PR 21507
Changes from previous version:
2.6.3 fixes a UI pause problem introduced in 2.6
2.6.2 bug fixes
2.6.1 generalised sequence handling
- replace the "unseen" window with a sequences window, and add a
Sequence menu.
- display number of unseen messages in folder cache
2.6 Add a Sequences menu, and internal overhaul of sequence handling
Bellovin in PR 13990. Changes are bug fixes, and a few enhancements,
a lot of them related to PGP and gpg. This upgrade also closes the
security hole in 2.1.1.
