Warn user when no meters in metrics panel

Avoid generating an exception by first checking if there is a
meter before calling replace method on it.
Give the user a nice warning if there are no meters available. This cannot be
done in the get method because this is an AJAX call to fetch JSON data.

Change-Id: I1536474c85083fb0bb3876e6650a3c928625a5c5
Closes-bug: #1274823
Don't copy the flavorid when updating flavors

The Nova API makes the implicit assumption that flavorids are unique,
so if one creates two flavors with the same flavorid, subsequent
requests for flavor information can vary between "inaccurate" and
"wildly f*cking inaccurate"

From an end-user perspective, it makes it look like data such as
flavor access settings get lost between edits (because the API pulls
the access list from the wrong flavor)

Let the API assign a new flavorid on changes.  The comments around
the handler code imply that is the desired behaviour, anyhow.

Change-Id: I5403202396a7b136b0ae8637d6aae1cf32550747
Closes-Bug: 1276371
Policy check needs to check for None in target

For objects that don't have a project_id attached to them, the
property can be set to None, which does not get overridden in
the policy engine where it being not set currently does.  This
adds a check for user_id and project_id being None and setting them
if they are.

Change-Id: I7aeb6d3830a19a7191de9944f8de90ee12dbf127
Closes-bug: #1274053
Adds meta and head-js partials to head in base.html

Allows users to add custom meta tags or javascripts to the base template

Implements: blueprint customizable-head
Change-Id: I40df3705a7ebe135d0f2843e1dcaa07e4ebcaaed
Merge "Don't copy the flavorid when updating flavors"
Merge "Policy check needs to check for None in target"
Merge "Adds meta and head-js partials to head in base.html"
Merge "Warn user when no meters in metrics panel"