Only accept newer revisions.

It seems like sometimes we get both an ACCEPT_COMMIT and a USER_CHANGES for the same rev...
fix editing several lines in
allow/require changes to be made through the Talker

I'll need follows for this to really be useful
added follow code, still buggy

I'm running into a weird issue where I'm not getting the ACCEPT_COMMIT messages the server says it is sending
modification to socket.io to use two separate threads for send and recv

This seems to clear up the issue with the vanishing ACCEPT_COMMIT, trying to send and receive interleaved on the same connection seems to have been the trouble.