Implement some logic in abstract methods

Since there're some checks that will be common between implementations
(MIN_TTL <= TTL <= MAX_TTL, for example), this patch adds a first set of
logic and tests fro *Base classes

Implements blueprint storage-base

Change-Id: I9e543ef2e2624bd5483e6d2392d0a9aeff5b0416
Updated README file with Marconi's goal.

Change-Id: Iad8d55ba1e23600b21ed3a4138c1aac07d16f0e6
Added tenant to the *ControllerBaseTest

Tenant was missing in base tests. This patch adds it to every test.

Implements blueprint storage-base

Change-Id: I71e677dc062f5798e75aaf19778956df6b0a89e0
Merge "Implement some logic in abstract methods"
Merge "Added tenant to the *ControllerBaseTest"
Replace create / update with upsert

This patch replaces both methods with a single method upsert. The idea
behind it, as discussed, is to have a single method for handling queue
creation and update.

The method is expected to return Ture when a queue was created and False
when a queue was updated.

Implements blueprint storage-base
Fixes bug 1155657

Change-Id: I367c5a29038acc89dbf60a3df9d8dcbf436037a7
Metadata is not optional (to storage).

Test cases are not affected.

Change-Id: I8dd90839cb87fbccf57544f8068eece513a35bb2
Add py26 to tox.ini

Change-Id: I043b8ac5d9c331f92d03267b8d2ae65f6346f222
Implementation of the reference storage.

Implements: blueprint storage-reference

Change-Id: I7b270208344e76a892e3bead764ba8b68fabca4d