Expose new merging operation for adding md_entry fields to fs_entry.
Expose new merging operation for adding md_entry fields to fs_entry.

iychoi/syndicate,jcnelson/syndicate,jcnelson/syndicate,iychoi/syndicate,jcnelson/syndicate,iychoi/syndicate,iychoi/syndicate,jcnelson/syndicate,jcnelson/syndicate,iychoi/syndicate,iychoi/syndicate,iychoi/syndicate,jcnelson/syndicate,jcnelson/syndicate,jcnelson/syndicate,iychoi/syndicate