Edited Issue: Remove default namespaces from XML in Web API [413]

The XML serialisation process injects default namespaces into the generated XML:

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http://www.w3.org/2001/XMLSchema"

These can be supressed in the XmlSerializer by explicitly passing in an XmlSerializerNamespaces object to the Serialize method.

I would be happy to develop a fix for this and submit a pull request if the team feel it is useful.