Merge pull request #751 from DavidRagazzi/master

Integration with nupic.core API
Change README to simplify environment variable documentation.
Update README with Marek's comments and update Dockerfile accordingly.
Restore run_tests.sh
Merge pull request #783 from scottpurdy/readme

Change README to simplify environment variable documentation.
Fixup run_tests.sh to do a cleaner pushd/popd directory change, update typo in help text
Merge pull request #785 from oxtopus/restore-run_tests.sh

Restore run_tests.sh
Merge branch 'master' of github.com:numenta/nupic into env-variables