Re: pglogical_output - a general purpose logical decoding output plugin

First, I wonder if it would be useful to mention somewhere, even if it's only here in the mailing list how can the protocol be extended in non-breaking way in future for transaction streaming if we ever get that.

The other thing is that I think we don't need the "forward_changesets" parameter which currently decides if to forward changes that didn't originate on local node. There is already hook for origin filtering which provides same functionality in more flexible way so it seems redundant to also have special boolean option for it.