Re: Timeline following for logical slots

I don't like reverting patches, but this patch is making me more and
more uncomfortable.  We have two open items, one of which requires
writing new test code that doesn't exist yet; and we have the
pg_recvlogical changes that were approved post-feature freeze, but that
I now have second thoughts about pushing right away.
Craig has also commented on some followup patch to change this whole
area in 9.7.

Per
https://www.postgresql.org/message-id/20160503165812.GA29604%40alvherre.pgsql
I think the best course of action is to revert the whole feature and
revisit for 9.7.

Here's a proposed revert patch.  Many minor changes (mostly comment
additions) that were applied as part of this series are kept intact.
The test_slot_timeline test module and corresponding recovery test
script are also reverted.

--
Álvaro Herrera                http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services