Chunk server: fix write append forwarding of close op with authentication / chunk access tokens by copying the tokens into the clone of the original close op. Fix write append commit ack with chunk access tokens by copying the tokens from write lease.
Meta server: remove unused flag in meta request base class. Emit numeric user and group ids in lookup replies in the case when no user or group id to name mapping exists to ensure that the client can reliably detect use meta server's user and group name mappings, instead of the local os mappings.
Client lib: do not set effective user and group with create and mkdir, do not attempt to check access permissions in open with authentication on, as the user and group data base only exists on the meta server side. Make root directory lookup first rpc, and set user and group data base mode accordingly, in order to make the result of subsequent calls / kfs client methods consistent.