Sync Rep for 2011CF1

Here's the latest patch for sync rep.

>From here, I will be developing the patch further on public git
repository towards commit. My expectation is that commit is at least 2
weeks away, though there are no major unresolved problems. I expect
essential follow on patches to continue for a further 2-4 weeks after
that first commit.

I will add my own reviewer's notes tomorrow.

In terms of testing, the patch hasn't been tested further than my own
laptop as yet, so it seems likely there's a few trivial howlers in
there. That is simply because of my recent flu.

I've requested Heikki as main reviewer and he's accepted. Other comments
are also welcome about the user interface and the reply protocol are
also welcome. Please don't bother performance testing yet. I'll let you
know when that is appropriate.

--
Simon Riggs http://www.2ndQuadrant.com/books/
PostgreSQL Development, 24x7 Support, Training and Services