2.0.4: stop using setuptools library to get current software version

• stop using setuptools library to get current software version

small bugfix release

• bugfix: NameError: when debug=True is used with asyncio.run, #75

small bugfix release

• bugfix: NameError: name 'sleep' is not defined in stream_writer.py

bugfix release

• bugfix: "write after close" is disregarded, caused many errors logged in socket.send()
• bugfix: in accessories.repr_mapping() about using shlex.quote on non-str,
  TypeError: expected string or bytes-like object, got 'int'
• bugfix: about fn_encoding using repr() on TelnetReaderUnicode
• bugfix: TelnetReader.is_closing() raises AttributeError
• deprecation: TelnetReader.close and TelnetReader.connection_closed emit
  warning, use at_eof() and feed_eof() instead.
• deprecation: the loop argument are is no longer accepted by TelnetReader.
• enhancement: Add Generic Mud Communication Protocol support :ghissue:63 by
  @gtaylor!
• change: TelnetReader and TelnetWriter no longer derive from
  asyncio.StreamReader and asyncio.StreamWriter, this fixes some TypeError
  in signatures and runtime

Python 3.11 support, drop 3.6 and older

major

• Support Python 3.9, 3.10, 3.11. Drop Python 3.6 and earlier, All code
  and examples have been updated to the new-style PEP-492 syntax.
• the loop, event_loop, and log arguments are no longer accepted to
  any class initializers.
• The asyncio Future, TelnetServer.waiter_encoding, now receives
  only a boolean, rather than an instance of TelnetServer (self).
• This release has a known memory leak when using the _waiter_connected and
  _waiter_closed arguments to Client or Shell class initializers, please do
  not use them. A replacement "wait_for_negotiation" awaitable will be provided
  in a future release.

minor

• std. python telnetlib is no longer imported, its constants are
  extracted directly to avoid DeprecationWarning
• some changes in CI/tox about dropping/adding python support, etc.
• skip pexpect tests with py3.10 until I can find the time to also
  devote time to maintain that library to fix asyncio compatibility
  issues
• small fix in repr_mapping() to use shlex to make values containing
  spaces conditionally quoted
• small race condition fix for waiter_closed
• small race condition fix for repr(BaseClient) and Server,
  around "peername" and in get_extra_info()

bugfix server-side exception on client disconnect

• bugfix a NoneType error on EOF/Timeout, introduced in previous
  version 1.0.3, #51 by @zofy.

Bugfix circular reference

• bugfix circular reference between transport and protocol, #43 by @fried

Add --speed option for telnetlib3-client

Telnet client negotiates speed, defaults to 38400. Thanks @hughpyle #35

Python 3.7 compatibility

Python 3.7 compatibility (#33)

• Fix syntax errors in python 3.7 due to async being a reserved word
• Update tests to use await/async syntax
• drop python3.4 and custom coverage combining
• document 1.0.1 release, project status: seeking new owner :-)

1.0 API release

After a year or more of refactoring, we release this new 1.0 API for the telnet protocol. This release prefers the shell(reader, writer) callback rather than the twisted-style subclassing of data_received in the previous version.