ODL issue where mounting fails if device augments netconf-state

ODL currently gets the netconf-state in order to obtain the list of device schemas. However if netconf-state is augmented, ODL cannot deserialize the response using Java binding classes since at that stage it is missing the additional modules required.

A potential solution is to relax the parsing of the netconf-state XML response so that the list of schemas can be read without deserializing.