Lets the cloud administrator create the freepool

And no more create it in plugin setup.

Fixes bug #1282534

Change-Id: I07b6bf562bba6728368d63707ffd9b2e906ab523
Devstack : create the freepool used by reservation host plugin

Change-Id: Ib8ddefe5030afc82246c48ec52acec0126a4cf29
Merge "Lets the cloud administrator create the freepool"
Merge "Devstack : create the freepool used by reservation host plugin"