We should not transition to apt.postgresql.org until we have a PPA

Folks,

I was just setting up a new PostgreSQL ubuntu server, and was kind of
stunned by the unnecessary complexity of the install instructions at
http://www.postgresql.org/download/linux/ubuntu/.  Also, they don't work.

If we're going to move our users to apt.postgresql.org, we really need
to provide a PPA for easy install.  Until we do that, we shouldn't
deprecate Martin's backports, which are easy to install and well-maintained.

-- 
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com