Building on HADOOP-13573 and HADOOP-13452, implement move() in LocalMetadataStore and associated MetadataStore unit tests.
(Making this a separate JIRA to break up work into decent-sized and reviewable chunks.)
S3Guard: Implement access policy for intra-client consistency with in-memory metadata store.
S3Guard: create basic contract tests for MetadataStore implementations
S3Guard: S3AFileSystem Integration with MetadataStore