Meta server: fix user and group names with file attribute response by de-referencing the string pointer.
Client lib: populate user and group name / id tables from lookup and read dir plus meta server responses, instead of using host os password and group databases, if any relevant meta server response contains user and/or group name. The decision to use the meta server supplied name / id mappings is irrevocable for the rest of the kfs client lifetime. Therefore changing the meta server configuration to turn off authentication, and as a consequence implicitly selecting "old" user and group mapping that uses host os password and group databases, requires creating kfs client from scratch. The present scheme does not invalidate possible stale user and group id to name mappings. For example, removing user database entry on the meta server will have no effect on the client -- the corresponding entry might remain in the client cache for the rest of the client lifetime, though will only affect i-node entries with matching user id. The i-node entry expiration and subsequent re-validation will update i-node user id and user name to id mapping if it changes. At this time I have no plan to address this deficiency as password and group database entries removals should typically be rare enough, and only affect uid to name mapping, and the size of the lookup tables.