[schedule] bzr 2.2b4 and rc1

[Martin Pool]

It's now time for bzr 2.2b4, after which we're going to split off a
2.2 branch from trunk.  jam has volunteered to do this tomorrow,
Friday, US time.

We found some bugs in the previous 2.2b3 packaging on Windows which I
believe are now fixed in trunk, so that makes it a good time to roll
another beta.

The 2.2 branch will then be in "api freeze mode", which means any
plugin that is updated to work against 2.2b4 will work against 2.2.0,
.1, etc.  You can still land bug fixes, features, optimizations and
documentation into 2.2.  You should not land anything that breaks or
deprecates any APIs without a compelling reason.

At the end of July we'll directly release 2.2.0 off the 2.2 branch,
and then continue doing point releases from that as appropriate.

There are no special restrictions on trunk.

A few actions from here:
 * [jam] actually make 2.2b4 and a pqm-managed 2.2 branch
 * [vila] test 2.2 on babune, ideally with some plugins?
 * [mbp] put 2.2b4 into the bzr-beta-ppa
 * [?] put 2.2b4 into debian unstable and ubuntu Maverick
 * [various] update plugins to work with 2.2, and if appropriate make
a 2.2 branch
 * [garyvdm?] package 2.2b4 for Windows

There are some good bugs in
<https://edge.launchpad.net/bzr/+milestone/2.2.0> for people to work
on for 2.2.

-- 
Martin