Commit 4ccb9caa1293e3d0e4e5feb6f90319050692f42f in isis's branch refs/heads/
ISIS-993 from Dan Haywood
[ https://git-wip-us.apache.org/repos/asf?p=isis.git;h=4ccb9ca ]
ISIS-1311: sorted out issue with Persistable mixins (return Long, not Object, otherwise trips up).
Also, fixed issue with tables that were incorrectly showing the datanucleusId and datanucleusVersion because of how check for HiddenFacets against mixin associations. Now generalized/improved the lookup of facet (had a different facetType key in the ObjectAssociationMixin compared to the underlying ObjectActionDefault).