[Server][CacheServiceDBClient] Add a new function: getConfig()
[Server][UnifiedDataStore] Add a new signature for OperationPrivilege.
[Server][DBClientConfig] Change a type of the addTargetServer() function.

void ->
HatoholError
[Server][UnifiedDataStore] Use CacheServiceDBClient.
[Server][FaceRest] Get OperationPrivilege.
[Server][FaceRest] Read username parameter and password parameter.

These parameters are forgotten to read by me...