Story 4258: CAP XML is parsed into an object

* A sample CAP XML file is successfully parsed into a `org.jdom2.Document` object. XML is also validated against the CAP XSD. 
* A sample invalid CAP XML document properly fails build when validated against CAP XSD.

[Story Link](https://cloud.agilefant.com/ahoffmann/editProject.action?projectId=99353#fi.hut.soberit.agilefant.model.Story_425854)