Changed the semantics of IpAddress.equals() to (eventually) return true
if both objects are instanceof IpAddress.
I.e., comparing IpAddress and Ip4Address objects could return true
if the underlying value is same.

Applied the same change to IpPrefix.equals() as well.

Change-Id: Ie0644565501d3ecce2a8603117b994d033d5b82f
2 files changed