2.1.0

• This version is fully backwards compatible with 2.0.*. However, it contains a
  few new API's that mimic the VObject 3 API. This allows it to be used a
  'bridge' version. Specifically, this new version exists so SabreDAV 1.7 and
  1.8 can run with both the 2 and 3 versions of this library.
• Added: Property\DateTime::hasTime().
• Added: Property\MultiDateTime::hasTime().
• Added: Property::getValue().
• Added: Document class.
• Added: Document::createComponent and Document::createProperty.
• Added: Parameter::getValue().