Tests: add testing Dockerfile. Impl fixes.

Tests: add testing Dockerfile. Impl fixes.

- tests/docker/Dockerfile: specifies full docker image containing all
  tools/languages (except matlab).
- tests/docker-build.sh: build above image.
- tests/docker-run.sh: launch above image.
    Example: ./tests/docker-run.sh make test^js^step2
- Various fixes across multiple languages:
    - Unicode fixes for bash and R on Ubuntu Utopic
    - readline history fixes for when ~/.mal-history is not available
      or readable/writable. No fatal errors.
    - fixes to work with perl 5.20 (and still perl 5.18)