Nuqql

* Add aborting of an ongoing search in a log window with the `ESC` key
* Add `--dir` command line argument for nuqql's config and working directory
* Cleanups and improvements
* Requires nuqql-slixmppd v0.8.0, nuqql-matrixd-nio v0.3.0,
nuqql-mattermostd v0.3.0, nuqql-matrixd v0.6.0, or purpled v0.6.0

* Set default `ESC` delay to 100ms and add the `--escdelay` command line
argument for configuring it
* Update backend handling
* Expect backends to send own messages in group chats back to nuqql with the
sender `<self>` and handle these messages accordingly
* Disable collecting accounts from backends and rely on the backend setting
`--push-accounts`
* Start purpled like other backends
* Requires nuqql-slixmppd v0.7.0, nuqql-matrixd v0.5.0,
nuqql-matrixd-nio v0.2.0, nuqql-mattermostd v0.2.0, or purpled v0.6.0

* UI changes
* Add welcome screen
* Improve scrolling to the left/right in input window
* Add missing packages to setup.py; pip installation should work now
* Cleanups, fixes and improvements
* Requires nuqql-slixmppd v0.6.0, nuqql-matrixd v0.4.0,
nuqql-matrixd-nio v0.1.0, nuqql-mattermostd v0.1.0, or purpled v0.5

* Add backend support:
* nuqql-matrixd-nio
* nuqql-mattermostd
* Always zoom Log Window when entering and change search input
* Add logging and the "--loglevel" command line argument
* Improve backend handling
* Update backend interface documentation:
* Add "version" command
* Cleanups, fixes, and improvements
* Requires nuqql-slixmppd v0.6.0, nuqql-matrixd v0.4.0,
nuqql-matrixd-nio v0.1.0, nuqql-mattermostd v0.1.0, or purpled v0.5

* Add version information
* Add `--version` command line argument
* Add `version` command to the nuqql conversation
* Backend changes:
* Change expected names of python backend executables to `nuqql-based`,
`nuqql-matrixd`, and `nuqql-slixmppd`
* Do not run `nuqql-based` by default any more
* Disable additional message history in python backends
* Improve backspace and quit handling
* Improve LogWin zooming and searching
* Add jumping and zooming from InputWin with `F9`
* Search for next match with `F10`
* Rename `nuqql.py` helper script to `run.py`
* Add `setup.py` for installation and package distribution
* Move nuqql-keys into the `tools/` subfolder and install it as `nuqql-keys`
with `setup.py`
* Add python type annotations
* Fixes and improvements
* Requires nuqql-slixmppd v0.5, nuqql-matrixd v0.3, or purpled v0.5

* Improve backend handling
* Add "stop", "start", and "restart" commands to nuqql conversation for
stopping, starting, and restarting a backend
* Handle "bye" and "quit" backend commands in nuqql
* Improve backend error handling
* Improve Log Window scrolling and message printing
* Add and use "chat msg" message format for group chat messages
* Add documentation of
* nuqql controls in `doc/controls.md`
* nuqql backend interface in `doc/backend-interface.md`
* Cleanups, fixes, and improvements.
* Requires purpled v0.5, nuqql-slixmppd v0.4, or nuqql-matrixd v0.2