Common library: fix fcntl() invocation in buffered log writer (this now makes it work with valgrind).
Meta server: implement "get authentication info only" flag with lookup RPC, to allow backward compatible way of determining the authenticated user and group ids and the corresponding names, group name, and effective user and group ids and names.
Client library: fix chunk server and chunk access tokens retrieval with lease acquisition and renewal by resetting chunk access tokens before re-acquiring the lease in order to prevent using stale chunk access tokens obtained by the last lease renewal.
Client library: implement delegation token info method. Implement get authentication info with look up RPC. Use the information obtained with get authentication info rpc to set authenticated and effective user and group ids, names, and the user and group data base mode. Return and error if kfs client init method is invoked after the client is already successfully initialized. Allow to change default client full sparse file support mode by setting client.fullSparseFileSupport property.
Qfs tool: implement "dtinfo" command to display all delegation token's properties, except the signature. Allow select sparse files read modes with fs.readSkipHoles and fs.readFullSparseFileSupport properties.
Qfs end to end test: update valgrind options.