Under certain circumstances, appears that auditing can cause the same tuple to be audited within a single transaction.

In the case of the Isis addon's implementation of auditing, there is a unique key constraint on (xactn/object oid/propertyId). This should indeed be unique.

However, for a large xactn (in isis-app-todoapp) found certain circumstances when the "changedProperties" map (keyed by AdapterAndProperty) seems to hold entries that violate this constraint.

Fix is to implement the hashCode/equals of AdapterAndProperty in a fashion in a more straightforward way.