Language tests.

  >>> from plone.app.i18n.locales.interfaces import IContentLanguages
  >>> from plone.app.i18n.locales.interfaces import IMetadataLanguages
  >>> from zope.component import queryUtility

  >>> util = queryUtility(IContentLanguages)
  >>> util
  <ContentLanguages at ...>

  >>> languagecodes = util.getAvailableLanguages()
  >>> len(languagecodes)
  1

  >>> u'en' in languagecodes
  True



  >>> util = queryUtility(IMetadataLanguages)
  >>> util
  <MetadataLanguages at ...>

  >>> languagecodes = util.getAvailableLanguages()
  >>> len(languagecodes)
  1

  >>> u'en' in languagecodes
  True
