shell: Fix dashboard plot highlighting

 * There is no "series-plot" data attribute, so find the series
   belonging to an item via the address.

 * Only move the plot to the front when turning the highlight on, not
   when turning it off.

Closes #1572
Reviewed-by: Stef Walter <stefw@redhat.com>
base: Distribute mustache and bring it into base package

This is a simple templating library that fits quite well with jQuery
and our method of operation. We don't currently do incremental DOM
updates, but that will come in a later iteration.
shell: Use Mustache to render the Servers on the dashboard

Note that we can't use .data() with data-* attributes as these
may change underneath jQuery.