Refactoring of DHIS API routines initial completion
1. Remove DhisXmlUtils and ...Test, add DhisMetadataUtils and ...Test
2. Add OrgUnitDisplay and ...Test
3. ServerMetadata and ...Test modified to be jaxb output handler
4. Further mods to hbms, pojos and DAO to incorporate OpenmrsDhisObject
5. Additional routines for DhisService, ...Impl and ...Test