Next pretest, and branching plans

[Chong Yidong]

I will roll the next pretest, 23.1.93, next week, Friday the 26th of
February.

Shortly afterwards, around Monday 1 March, we will make the release
branch, which will be used for all subsequent 23.1.xx pretests, as well
as the final 23.2 release.  Once this branch is made, the feature freeze
will be made "harder".  Except for documentation improvements and
special exceptions (which must first be discussed on emacs-devel, or
with Stefan or myself), the only allowed bugfixes are for regressions
with respect to Emacs 22.

(At a still later date, we will only allow bugfixes for regressions with
respect to Emacs 23.1.)

Once the branch is made, Stefan or myself will announce on emacs-devel
that the trunk is open for Emacs 24 development.  At this point, we can
merge the projects from the pending branch into the trunk, and so forth.
We'll give more details about commit policy for the trunk, and our
general goals for Emacs 24, later.  (Opinions are welcome.)

Once the branch is made, some bugfixes will need to be applied both to
the trunk and to the branch.  This is important, so anyone who has
commit access should take note.