Added handoff.ip field and validator (addresses #634)
Added schema tests for handoff.ip
Added a validator test for loopback addresses
Validator now confirms a sane IP rather than non-loopback
Merge pull request #653 from basho/bugfix/atb/add-handoff-ip-to-schema

Add handoff.ip to core cuttlefish schema

Reviewed-by: andrewjstone