Config module no longer remember cli args.

 - The .set_cli method is dropped;
 - .load method now accept an 'args' argument instead;
 - no cli args is read by default when 'args' is None.

Implements: blueprint config-module

Change-Id: Ic41904a584495170d8ca26c93c0d68e708469cc6
Queue stats returns claimed, expired, and total.

Change-Id: I665b385a0bf6ac2fd702615df94d440031c4928c
Implements: blueprint storage-base
Implements: blueprint storage-reference