GLASSFISH-21148 Fixed parsing principal from metadata

- prinicpal was parsed, but metadata were not updated
GLASSFISH-21148 More descriptive exception messages
GLASSFISH-21219 Using HashMap instead of HashSet

- Session.hashCode may change (serializable)
GLASSFISH-21219 Using HashMap instead of HashSet (HA/SSO)
GLASSFISH-21146 Fixed NPE in log

- avoid toString call (implicit and safer for null values)
- debug replaced with logging level FINE
Merge branch 'GLASSFISH-21148' into master-dmatej

* GLASSFISH-21148:
  GLASSFISH-21148 More descriptive exception messages
  GLASSFISH-21148 Fixed parsing principal from metadata
Merge branch 'GLASSFISH-21219' into master-dmatej

* GLASSFISH-21219:
  GLASSFISH-21219 Using HashMap instead of HashSet (HA/SSO)
  GLASSFISH-21219 Using HashMap instead of HashSet
Merge branch 'GLASSFISH-21146' into master-dmatej

* GLASSFISH-21146:
  GLASSFISH-21146 Fixed NPE in log