------------------
- Fix issue where values of indicators (sequence/choice/all) would
write to the same internal dict. (425)
- Set default XML parse mode to strict as was intended (332)
- Add support for pickling value objects (417)
- Add explicit Nil value via ``zeep.xsd.Nil`` (424)
- Add xml_huge_tree kwarg to the Client() to enable lxml's huge_tree mode,
this is disabled by default (332)
- Add support to pass base-types to type extensions (416)
- Handle wsdl errors more gracefully by disabling the invalid operations
instead of raising an exception (407, 387)