No longer need to remove backend query element, since it's no longer valid
Make select2 pre-fill with previously selected metrics

Plus - change the graph controller to remove empties (placeholder) and use
metrics returned as the full set.

Bugs ahoy as select2 assumes an ID and Text for formatSelection and id
functions. Could change the json feed to format my own outputs, but I really
can't be bothered.
If space in seaerch, sub with wildcard
Convert to sliding window updates

Also, use rounded y-axis labels
Convert to sliding window updates

Instead of shifting old data and appending new data, get a sliding window of
updates, that being, the difference between start and stop, relative to "now".
This data replaces all previous data, so set this as the graph's contents (as
opposed to pushing onto the end)
Re-enable play/stop functionality and button in navbar
Put slider and chart into col div to prevent slider slipping off to the left on epic window width, batman
Use Time.Precise.Local to make X-Axis more pretty

From glasnt/rickshaw:Time.Precise branch