Putting Toolchains and Regression inside Docker with Scripts

Created by: Karl-Han

There are two parts in this PR:

• Dockerfiles/Container/Commandline for
  • Open-Source Toolchains including buildroot
  • Automatic Regressions within Docker
• Easy-to-use scripts
  • main start-up script: start.sh to start the command line within container
  • assistive scripts: not intended to be used directly but for reference
    • get_images.sh: get necessary Docker images by fetching (default)
    • run_regression.sh: used in automatic regression

See Dockerfiles README for detailed documentations.

Please try it out and give me some feedbacks on better documentations and easier start-up script.