REFACTOR clean up unused methods, and other minor changes
REFACTOR throwing TenantNotFoundException if current tenant not found, instead of IllegalArgumentException
FIX concurrency issues with global variable 'token'; better error handling & messages; improved logic when requesting profile to other PS
FIX consistency change: removed Tenant parameter from addProfile() in UserManager; tenant should be set in TenantContextHolder
REFACTOR renamed DB entities methods to add 'ByTenant' when necessary; improved exception handling
FIX URL in logged message
FEATURE added rdf:type PersonContact in case the API controller try to by-pass this
FIX can remove all members from a PersonGroup instance