Added integration tests for marshaller utils and data element marshaller.....nearly finished making the integration tests use variable ids
Merge branch 'develop' of github.com:MetadataRegistry/ModelCataloguePlugin into develop

Conflicts:
	ModelCatalogueCorePlugin/test/integration/uk/co/mc/core/DataElementControllerISpec.groovy
added variables into tests for id's etc.
Merge branch 'develop' of github.com:MetadataRegistry/ModelCataloguePlugin into develop

Conflicts:
	ModelCatalogueCorePlugin/grails-app/domain/uk/co/mc/core/CatalogueElement.groovy
	ModelCatalogueCorePlugin/test/integration/uk/co/mc/core/DataElementISpec.groovy
	ModelCatalogueCorePlugin/test/integration/uk/co/mc/core/RelationshipISpec.groovy
single test with exactly the same parameters passes whilst params in the where clause do not