Add more example links in docs.
Rerun features notebook.

There were errors in the stored output before.
Merge pull request #581 from enthought/feature/add-nbviewer-links-in-docs

Add nbviewer links in docs
Merge pull request #580 from enthought/refactor/nonce-and-basename

Refactoring: nonce() and DISTARRAY_BASE_NAME
Merge branch 'master' into feature/lazy-evaluation