sort the panel's variable in the dashboards.py

[tinytmy]

In the dashboards.py some PanelGroup's variable use(slug,name.panels),
(https://github.com/openstack/horizon/blob/master/openstack_dashboard/dashboards/project/dashboard.py#L20-L23)
and some use(name, slug, panels),
(https://github.com/openstack/horizon/blob/master/openstack_dashboard/dashboards/project/dashboard.py#L47-L51)
 we can unit it, used as
(https://github.com/openstack/horizon/blob/master/horizon/base.py#L294-L319)

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/169961

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/169961
Committed: https://git.openstack.org/cgit/openstack/horizon/commit/?id=ebdb7313f1d346aaa047901228548b86df6727f0
Submitter: Jenkins
Branch: master

commit ebdb7313f1d346aaa047901228548b86df6727f0
Author: tinytmy <email address hidden>
Date: Thu Apr 2 08:50:52 2015 +0800

    Sort the panel's variable in the dashboards.py

    In the dashboards.py some PanelGroup's variable
    use(slug,name.panels), and some use(name, slug, panels),
    we can unit it, used as(slug,name.panels).

    Change-Id: If508fcb59c372c581938152db8bceb4ed849c256
    Closes-bug:#1438984