Merge changes Ibe956014,I4222b894,Iac4ea144,I803717e8,I39e97dcd, ...

* changes:
  Support updating multiple VersionedMetaDatas in a BatchRefUpdate
  Refactor byChange() into two methods: drafts and published
  Add draft comments to PatchLineCommentsUtil
  Fix bug for comments with no range
  Resolve issue with naming of drafts ref
  Add method to parse an AccountId out of a RefName
  Improve PatchSet.Id.fromRef performance and avoid double-parsing