Revisit the hashCode(...) method, since we had an inconsistency with equals(...) in the way to take in account which interface is implemented.
While fixing the inconsistency, we opportunistically lined-up the API with the equals(…, ComparisonMode) one,
in the hope to be more future-proof regarding possible SIS API evolution.


git-svn-id: https://svn.apache.org/repos/asf/sis/branches/JDK7@1519807 13f79535-47bb-0310-9956-ffa450edef68