Lots of changes

** DONE Track authorship in-buffer via properties
   ~crdt-visualize-author-mode~ UI
** DONE Make interactive changes to crdt-version and crdt-connect
** DONE Stop leaking ip address
** DONE Investigate why xref-find-definitions causes error
** DONE Figure out the code for colouring selection colours from
   ‘default’s :background

- gracefully degrade when TLS handshake fail (I hope it works)
- remove session name settings