* Add Validations.LedgerSeq and .InitialSeq fields.
* Clean up logging.
* Lower online delete minimum for standalone mode.
* Unit tests of online_delete.
This implements the tracking of when an amendment achieved a majority
in the ledger, ensuring that there's always network-wide agreement
on which amendments have achieved a majority and how long they've
held it.
* New fields
* Change transactor changes
* AmendmentTable API and implementation changes
* Update amendment enabled status on validated ledgers
* Reinstate support for ledger sequence in fee transactions
* Do not forward manifests to peers that already know that manifest
* Do not forward historical manifests to peers
* Save/Load ValidatorManifests from a database
* Python test for setting ephmeral keys
* Cleanup manifest interface
