adding 6 keywords

Added:
- intersect
- union
- volatile
- leakproof
- owner
- owned
Merge pull request #7 from fi5er/add-keywords

adding 6 keywords
Merge commit '2e8d8abe8b4860da1b95bea1ff322084dd596b51'

* commit '2e8d8abe8b4860da1b95bea1ff322084dd596b51':
  adding 6 keywords