Checklist for official releases
===============================
- test polyml-5.3.0, polyml-5.2.1, polyml-5.2, polyml-5.1, polyml-5.0;
- test Proof General;
- test Scala wrapper;
- check HTML header of library;
- check CTRL-C, SIGINT in tty (also for external processes);
- check persistent sessions with PG and Poly/ML 5.x;
- Admin/update-keywords;
- check ANNOUNCE, README, INSTALL, NEWS, COPYRIGHT, CONTRIBUTORS;
- diff NEWS wrt. last official release, which is read-only;
- update https://isabelle.in.tum.de/repos/website;
- maintain Docs:
doc-src/Dirs
doc/Contents
- maintain Logics:
build
lib/html/library_index_content.template