Postponement of v10 release schedule

Per the discussion in
https://www.postgresql.org/message-id/flat/20170909064853.25630.12825%40wrigleys.postgresql.org
it seems that our new trigger-transition-table feature isn't
really SQL-spec compliant. Rather than releasing v10 that way,
and then causing compatibility problems when we fix it later,
the release team has agreed that a slippage in the v10 schedule
is appropriate.

We considered doing a wrap this week anyway and calling it beta5,
but there hasn't really been enough change from beta4 to justify
the overhead of an extra packaging cycle. Accordingly, there will
be no release this week.

The current plan is to try to implement a fix for the trigger
semantics problem this week, and then put out 10rc1 next week.

I'm expecting that we will also slip 10.0 GA release one week,
although that could change depending on how messy the trigger fix
ends up being.

regards, tom lane