Changes pypi packagename to 'opencafe'. Adds plugins to sdist.

 * Changed the package name to 'opencafe' so that it's
   pip installable under that name, instead of 'cafe'
 * Added recursive include on plugin directory in the MANIFEST.in
   file to make sure everything under the plugins directory gets
   included in the sdist when published.

Change-Id: Ia09686ff08c2c4ddda6aa60908f98bba3d4ff64c
Merge "Changes pypi packagename to 'opencafe'. Adds plugins to sdist."