Adding panels for trove

* Add python-troveclient to requirements.
* Add trove api to openstack_dashboard apis.
* Add Database Instances panel.
* Add Database Backups panel.

Authors:
* Robert Myers
* Denis Makogon
* Andrea Giardini

Implements: Blueprint trove-support

Change-Id: I0541534612ccb491d692168c3c9ca7a841650be6
Fix help string for Host routes

Closes-Bug: 1219520
Change-Id: Ia70e91e566c8e1788b3972946dae10d9bebb6735
"# noqa" cleanup

This patch set replaces a few method imports with
module imports instead of "# noqa" comments.

Fixes bug 1219676

Change-Id: I4d99ec5cda556669737c1eae2f528fbd35590d60
Merge "Fix help string for Host routes"
Merge "Adding panels for trove"
Add metering panel to admin console

Now it has usage tables for disk usage,
network traffic usage, network(neutron) usage,
objectstore usage, all agregates of project.

A multiseries linechart with choosable meters, group by, value and time
span.

Reasonable amount of tests implemented over all resource usage tabs.

Change-Id: I21342d595ee08da45707e909f3d9802707d912cc
Implements: blueprint admin-resource-usage-page