Electrum 4.2.0 Release

March 16, 2022

Core Updates:
- Increased minimum Python version to 3.8 (#7661)
Lightning Network Improvements:
- Redesigned MPP (Multi-Path Payments) splitting algorithm (#7202)
- Implemented multi-trampoline MPP for improved routing (#7623)
- Added support for option_shutdown_anysegwit and lower dust limits (#7542)
- Implemented option_channel_type (#7636)
- Introduced modern closing negotiation (#7586, #7680)
Enhanced lightning: URI support across all platforms (#7301)
Qt GUI Enhancements:
- Added setting for displaying amounts with millisatoshi precision (5891e039)
- Introduced option to add thousand separators to Bitcoin amounts (#7427)
CLI/RPC Improvements:
- Implemented Unix sockets as default communication method (#7545, #7566)
- Added “bumpfee” command for fee bumping (#7438)
Kivy GUI (Mobile) Updates:
- Network setup now shown before wallet creation on first start (#7464)
- Added “Child Pays For Parent” (CPFP) option (#7487)
- Improved locale handling (22bb52d5, 7cb11ced, 4293d6ec)
Hardware Wallet Support:
- Trezor: Updated trezorlib to version 0.13 (#7590)
- BitBox02: Updated to version 6.0, added support for send-to-taproot (#7693)
- Ledger: Added support for Ledger Nano S Plus (#7692)
Library Enhancements:
- Added support for additional sighash types beyond “ALL” (#7453)
- Expanded signmessage to accept Trezor-type signatures for segwit addresses (#7668)
- Made network request timeout configurable (#7696)
- Improved paytomany functionality for onchain txout batching (#7492)
Build System:
- AppImage: Updated base image from Ubuntu 16.04 to 18.04 (5d0aa63a)
- Migrated from Travis CI to Cirrus CI (#7431)