fixes #878

fixes #975

Apparently the bug https://bugreports.qt.io/browse/QTBUG-99545 shouldn't
happen in the runtime anymore.

fixes #903

This adds a man page which lists command line options, key bindings and
commands. A new CMake option `MAN` is added, enabled by default on
`UNIX` but not `APPLE`.

The man pages are generated with either `a2x` (from asciidoc) or
`asciidoctor`. If both are not found, a fatal error is signaled.

See https://gitlab.gnome.org/GNOME/libsecret/-/issues/49

fixes #816

This was a bit of a journey:
https://github.com/matrix-org/matrix-doc/pull/3471
But it should work now and we now use the UIAHandler everywhere.

fixes #670

Add support for listing devices that do not support encryption, add support for logging out devices.

Ticks off another box in #23!

Showing the bootstrap state and showing there are unverified devices is
still missing.

fixes build with new libolm