Add JobDescription wrapper and refactor XML parsing

Change-Id: Iac31c6b97c5c46ad85e9213b3454cdb7c74be774
Signed-off-by: Denis Knoepfle <denis.knoepfle@sap.com>
Merge pull request #122 from DenisKnoepfle/master

Add JobDescription wrapper and refactor XML parsing