quotas shouldn't accept negative numbers other than (-1)

[Dan Prince]

As reported in:

#972034 -1 vs. None w/ Unlimited Quotas

Quotas should not accept negative numbers other than -1 (which is a flag value for unlimited).

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/6220

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/6220
Committed: http://github.com/openstack/nova/commit/c7dbed99d115989ad8d03db7dc3ffbcaa6fb78c3
Submitter: Jenkins
Branch: master

commit c7dbed99d115989ad8d03db7dc3ffbcaa6fb78c3
Author: Dan Prince <email address hidden>
Date: Wed Apr 4 09:38:59 2012 -0400

    Add validation on quota limits (negative numbers).

    Quotas should not accept negative numbers other than -1.

    Fixes LP Bug #973034.

    Change-Id: Icc647d80df42d09928717d48ae95dfc8b76c4795