Docs:  Make a "Cookbook" page for thorough examples/scenarios.

Also fixed a docstring in the Streams API.  Currently there is only
one scenario about using Streams.
Merge pull request #13 in PYTHON/python-devicecloud from docs to master

* commit 'eb2a292fc6269d4a95243cc92e7c9e224c9f1b19':
  Docs:  Make a "Cookbook" page for thorough examples/scenarios.
Merge remote-tracking branch 'origin/master'