Implement NewsML feeds, ported from collective.syndication.
Improve the body render feature rendering the content_core of the object instead of the body field.
Clean up newsml code, remove adapter and settings, manage everything in the view.
Move newsml_allowed and newsml_enabled from util to the view.
Test NewsML view and test render body option.
Fix i18n:domain
Merge pull request #151 from plone/syndication_improvements

Syndication improvements