[phpMyAdmin Developers] creating MAINT branches for each release

[Isaac Bennetch]

Currently, the release instructions prompt me to create a MAINT branch
for each release. That way, if we have a security fix for 4.6.2 we can
go to MAINT_4_6_2 and perform the work there. I think this is overkill
-- for instance, we haven't done a patch-level security release on 4.6.0
or 4.6.1.

If we need to do a security release, we can create the MAINT branch later:

git checkout RELEASE_4_6_2
git checkout -b MAINT_4_6_2

I'm proposing that we stop creating MAINT branches for each release.
This isn't something I feel particularly strongly about, so I could be
convinced to withdraw my proposal, but I don't see much value in
maintaining MAINT branches we aren't using.

A side-effect of this is that currently, the demo server has STABLE,
QA_4_6, and MAINT_4_6_2 [1]; QA_4_6 will change until our next release
and STABLE and MAINT_4_6_2 will remain the same unless we need to
release a 4.6.2.1, in which case both would be updated. For the demo
server, I may be missing a scenario but don't see how the current MAINT
and STABLE would differ, meaning we can remove MAINT from there as well.

1 - technically, the demo server currently has MAINT_4_6_1, but based on
response to this thread I'll update it soon.