[dpdk-dev] mempool: add stack mempool handler

[David Hunt]

This patch set adds a lifo stack handler to the external mempool
manager.

This patch set depends on the 3 part external mempool handler
patch set (v15 of the series):
http://dpdk.org/ml/archives/dev/2016-June/042004.html

v3 changes:
  * Updated based on the latest version (v15) of the Mempool Handler feature

v2 changes:
  * updated based on mailing list feedback (Thanks Stephen)
  * checkpatch fixes.

David Hunt (2)
  mempool: add stack (lifo) mempool handler
  test: add autotest for external mempool stack handler