added GroupDetailSelector so GroupPersistence implementation can configure whether group details should be returned from searches

Story ac2. Added UserClient to perform subject augmentation. Updated LdapUserDAO to add X500Principal. NumericPrincipal is to be added later when it is ready. Fixed UserActionFactory to ignore case when comparing idType.

ac2 rework: add JsonInputter to parse a json String into a DOM, updated JSON readers and writers to use the cadcUtil Json Inputter and Outputter.

implemented public-attribute-only get option so caller doesn't need permission to get a member group

Story ac2 rework. Removed getUserGroups() from the API since we already have getGroups(). This also stops us from exposing com.unboundid.ldap.sdk.DN to the API.