Adding status field to image location -- scrubber changes

Adding a status field to image's each location property, each location
status can be 'active', 'pending_delete' and 'deleted'.

Under location's status information Scrubber service can make cleanup
based on DB records also but not a dedicated queue-file for each image.

This is third part of this change which covered scrubber DB queue
enablement and double queue supporting.

Partially-Implements BP: image-location-status

Change-Id: I8ee9e9254c8371bbbce8b28d643e3d474b2361bc
Signed-off-by: Zhi Yan Liu <zhiyanl@cn.ibm.com>
Merge "Adding status field to image location -- scrubber changes"