SES-1728 : Convert Model to set and return Namespace objects
SES-1728 : Convert Model implementations to set and get Namespace
objects
SES-1728 : Revert change to getNamespace logic

Also enable caching for setNamespace to avoid redundant object storage
SES-1728 : Javadoc for ApacheSetTestCase
SES-1728 : Rename method to indicate that only literals are returned
SES-1728 : Refine types to indicate what is being tested in TestModel
SES-1730 : Add Comparable<Namespace> to Namespace interface contract
SES-1730 : Override equals and hashCode in NamespaceImpl
SES-1728 : Add tests for Namespace support in Model implementations
SES-1720 : Patch SPARQLResultsJSONWriter to support RDF-1.1
Merged in ansell/sesame/SES-1728 (pull request #63)

SES-1728 : Model.getNamespaces should return collection of Namespace objects
Merged in SES-1720 (pull request #66)

SES-1720 : Patch SPARQLResultsJSONWriter to support RDF-1.1