use topo_diff for user input changes

pretty large commit, but it mainly boils to
 - reusing the same format clone returns to the client for topo_diff

bad bad code introduced mainly in client side, but server wasn't spared:
 - graph/commit_topo__diff massages the links too much - this should not
   be there at all, it should be in the correct format to begin with.

server code duplication between clone & topo_diff post processing,
should be factored out

on the good side: single transaction whenever user presses enter, and
the correct place to send back any accumulated diffs (other user
changes).

0 files changed, 0 insertions, 0 deletions