I've read and tested through the latest version of this patchset and I think it's ready to go in. The one concern I have is that tasks can exit(1) on libpq errors tearing down perfectly functional connections without graceful shutdown. Longer term I think it would make sense to add similar exit handler callbacks to the ones in pg_dump for graceful cleanup of connections. However, in order to keep goalposts in clear view I don't think this patch need to have it, but it would be good to consider once in.
Spotted a small typo in the comments: + * nothing to process. This is primarily intended for the inital step in s/inital/initial/ -- Daniel Gustafsson
