v1.1.13

[alexrp]

• Implemented deduplication of nodes and attributes when serializing data center files.
• Added novadrop-dc schema command which can generate schemas from a data center file.
  • Note that these schemas still require a human touch as e.g. recursive structures cannot be determined accurately.
• Fixed some incorrect minOccurs/maxOccurs attributes in the set of embedded schemas.
• Fixed DataCenterExtensions.Descendants() returning nodes in the wrong order.