[2.0] allocation query: Minimum should become global to the query rather then per pool

Submitted by Nicolas Dufresne @ndufresne

Link to original bug (#746213)

Description

The minimum as found in allocation pool is the minimum buffer required by a segment of a pipeline to function. Having this minimum spread across the allocation pool array is inconvenient. In 2.0 we should most likely make this field global to the query so updating it is easier.

Version: 2.x