v1.1.0

Added a more complete API for parsing, serializing and pickling XML structures, including support for:

• <xs:all> (#4)
• <xs:choose minOccurs="0" maxOccurs="unbound"> (#6)
• namespaces (#8)

Besides that:

• Parser.orElse was improved (410f1e8)
• number conversions for Option[String] where added, similar to the conversions for String (10921be)