Extract QualifiedTypeProvidingFieldName from EntityName to make it more general.
Add CrudPersistence.save(Option[ID], SourceType, source, RequestContext)

It is a convenience method.
Also rename EntityType.idFieldDeclaration to id.
Create external functions for UriPath.

This is in preparation for inlining them to eliminate the UriPath class.
Add EntityNavigation.topLevelActions.
Made CommandId extend Name, and made Name more flexible.