Use of Iterable to simplify test specs

* ConsensusComparison uses Iterable/Iterator to iterate ConsensusEntryPairs
* ConsensusEntryPairs are Iterable to Iterate their columns
* org.mastercoin.consensus.DataPipeSpec demonstrates how to use in a Spock Specification
Rename in preparation for consolidated functionality
Refactor tests to use new Base Specs and test multiple currencies.
Change test packages after refactoring