- Implement KIWIXMLPXEDeployConfigData
  + <pxedeploy> supports multiple declarations of <configuration>
  + remove confArch, confDest, and confSource from KIWIXMLPXEDeployData
    and encapsulate in this new object
- Integrate KIWIXMLPXEDeployConfigData into XML
  + hold array of KIWIXMLPXEDeployConfigData and enforce child relationship
    to KIWIXMLPXEDeployData indirectly
- Implement proper default processing for partition definitions in
  KIWIXMLPXEDeployData
  + previously the default setting were applied in the XML in the old data
    model. In the new data model all default are known only to the type
    encapsulating the data
- Eliminate all *PXEDeploy*_legacy methods from XML class
  + update client code to use new data model provided objects
- Eliminate all calls to _legacy in the PXE image creation code path
- Implement new tests and update existing tests as necessary
  + new tests for new class
  + update tests for default values
  + new tests for default settings
  + eliminate _legacy tests for PXEDeploy