Summary
- clarified build_polyml_component;
- avoid mixture of symlinks and hardlinks, which causes problems with BSD tar on macOS Sierra;
- updated;
- more uniform line-oriented output, notably for scala-2.12.2 REPL which emits "\n" separately;
- tuned;
- suppress ANSI control sequences in Scala console;
- updated to scala-2.12.2;
- updated to jdk-8u131;
- updated to xz-java-1.6;
- separate keep auxiliary directory, to facilitate error diagnosis;