README updates:

- removed inline OPF examples in favor of links to Using Nupic wiki
  page, which contains examples, tutorials, and screencasts
- replaced ambiguous and non-executable example of running tests with a
  line-by-line runnable example of running tests from make
- added note about anomaly detection capabilities to project
  description
Adding tests_all
Merge branch 'master' of github.com:numenta/nupic into update-readme
Merge pull request #904 from rhyolight/update-readme

README updates:
Default directories structure (python standard)
$NTA replaced by $NUPIC
Adjustments to the new dir structure