fix(event): Chase etcd index on EcodeEventIndexCleared
refactor(registry): Use a single watcher in EventStream
refactor(registry): Check for path prefix in event filters
Merge pull request #411 from bcwaldon/chase-that-index

Chase that index
fix(registry): lazily migrate legacy payloads
Merge pull request #413 from bcwaldon/lazy-migrate

fix(registry): lazily migrate legacy payloads
refactor(registry): move fleetctl's Registry interface to registry proper