Summary
- show SSH options in PIDE GUI;
- inplace update: proper Linux version;
- provide naproche-20220917;
- clarified NEWS;
- proper platform directory x86_64-linux, to have it purged for other platforms; tuned README;
- MLton component for x86_64-linux;
- clarified Docker base image;
- proper file headers;
- tuned messages;
- support for ISABELLE_MLTON_OPTIONS, notably for Ubuntu 22.04 with external mlton executable;
- omit menu for unfinished tool;