Add `crdt-switch-to-buffer`

See merge request !3

between shared buffers, as an alternative to selecting a buffer from
the buffer list buffer.

- add crdt-toggle-override-command
- fix network coding, always use utf-8

feat: Option to put tuntox password in copied URL

See merge request qhong/crdt.el!2

Check if the process-mark is non-nil and if mark-pos is non-nil to prevent errors

See merge request qhong/crdt.el!1

** 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

also remove some debug printing

commit a80f73d8
Merge: 20ff83c8 2eddf967
Author: Qiantan Hong <qhong@mit.edu>
Date:   Fri Oct 1 15:34:50 2021 -0700

    Merge branch 'master' of code.librehq.com:qhong/crdt.el

commit 20ff83c8
Author: Qiantan Hong <qhong@mit.edu>
Date:   Fri Oct 1 15:34:07 2021 -0700

    fix a bug in buffer remove handler