2.2.0

2.2.0

• bugfix: workaround for Microsoft Telnet client crash on
  SB NEW_ENVIRON SEND, #24. Server now defers
  DO NEW_ENVIRON until TTYPE cycling identifies the client, skipping it
  entirely for MS Telnet (ANSI/VT100).
• bugfix: in handling of LINEMODE FORWARDMASK command bytes.
• bugfix: SLC fingerprinting byte handling.
• bugfix: send IAC GA (Go-Ahead) after prompts when SGA is not negotiated.
  Fixes hanging for MUD clients like Mudlet. PTY shell uses a 500ms idle
  timer. Use --never-send-ga to suppress like old behavior.
• performance: with 'smarter' negotiation, default connect_maxwait
  reduced from 4.0s to 1.5s.
• performance: both client and server protocol data_received methods
  have approximately ~50x throughput improvement in bulk data transfers.
• new: Server class returned by create_server() with
  wait_for_client() method and clients property for tracking
  connected clients.
• new: TelnetWriter.wait_for() and wait_for_condition()
  methods for waiting on telnet option negotiation state.
• new: telnetlib3.sync module with blocking (non-asyncio) APIs:
  TelnetConnection for clients, BlockingTelnetServer for servers.
• new: pty_shell module and demonstrating telnetlib3-server --pty-exec CLI argument
  and related --pty-raw server CLI option for raw PTY mode, used by most
  programs that handle their own terminal I/O.
• new: guard_shells module with --robot-check and --pty-fork-limit
  CLI arguments for connection limiting and bot detection.
• new: fingerprinting module for telnet client identification and
  capability probing.
• new: --send-environ client CLI option to control which environment
  variables are sent via NEW_ENVIRON. Default no longer includes HOME or
  SHELL.