Kfsio library: fix client authentication context destructor by invoking Clear() method.
Chunk server: fix lint warnings. Fix re-authentication in meta server state machine, by allowing to process the reply if its sequence number doesn't match the authentication's RPC sequence number in order to handle possible in flight / "on the wire" replies that the meta server can send before receiving the authentication RPC.
Meta server: eliminate lint warnings.
Client library: fix ssl shutdown, by clearing authentication context in the kfs client's shutdown method in order to ensure that all openssl structures are release before invoking openssl library cleanup. Fix invalid empty string de-reference in the cache invalidation with read dir plus of the root directory.