[plt-dev] Release for v4.2.3 is about to begin

The release process for v4.2.3 will begin in about one week (on the
15th). This means that the trunk is going to be copied into a branch --
please make sure that code that you're responsible for is as stable as
possible, and let Eli know if there is any new work that should not be
included in this release.

      >> NOW IS THE TIME TO FIX BUGS THAT YOU KNOW ABOUT <<<

The time between the branch and the actual release is for fixing new
errors that prevent a proper functioning of major components and that
show up during the preparation for a release.