OZF-210: Adding the top level IWC API REST ResourcE

Conflicts:
	grails-app/resources/marketplace/rest/resource/ApiResource.groovy
	grails-app/resources/marketplace/rest/resource/IwcDataObjectResource.groovy
	grails-app/resources/marketplace/rest/resource/IwcResource.groovy
	src/groovy/marketplace/hal/RelationType.groovy