ESPResSo 4.2.1 code freeze

[Jean-Noël Grad]

Dear users,

The ESPResSo team is happy to announce that the 4.2.1 bugfix release is 
almost ready. It addresses severe issues in the checkpointing mechanism, 
Brownian integration of fixed particles and reactions methods for 
concurrent reactions. You can see the complete list of improvements on 
our wiki [1] and try out an early version of the release in the 
corresponding PR [2].

Please note this will be the last release in the 4.2 line! If you are 
aware of bugs or have experienced issues with libraries or compilers, we 
would be grateful if you could let us know on the mailing list or on the 
issue tracker until January 31 2023, so that our team can investigate 
and take action before the release.

Best regards,
JN

Links:
[1] 
https://github.com/espressomd/espresso/wiki/es-421-release-notes#bug-fixes
[2] https://github.com/espressomd/espresso/pull/4611