Chunk server: remove redundant checksum vector clear() in chunk replicator.
Common lib: create default integer hash class implementation, make hash functor key value pair template parameter, make integer class functor default template parameter. Add HsiehHash() wrapper, and change length parameters to size_t instead of int.
Meta server: initial incomplete implementation of user and group information retrieval from the host os, and lookup / query logic. Use getpwent() to  retrieve user information, and getgrent() to retrieve group information. Use dedicated thread to perform periodic and/or scheduled updates of user and group information, and then pass newly retrieved information to the request servicing logic. Password and group information should have similar effect on qfs file system as with the typical unix file system, as it used to convert internal user and group ids into "names" / human readable representation. User or group entry removal will leave the corresponding user or group ids with no corresponding "names", and in such case decimal id will be used as human readable / string representation. However users that no longer exist will not be allowed to authenticate with the meta server, though existing authenticated connection will not be shutdown immediately in the case when user entry removal.