Migrate contributor agreements to All-Projects.

Added a new schema to move the ContributorAgreement, AccountAgreement,
and AccountGroupAgreement information into the All-Projects
project.config.

Updated VersionedMetaData to expose a way to do batch commits to the
meta data.

Change-Id: Ifb3fdd8c0d6a0c988941d6949f6501b8f8856412
7 files changed