[web-ui][stats][graph] Improved graph view and added stats view

CHANGELOG
=========
* Added `GraphboxView`, which is an extension of `Backpack.Lightbox`,
  but only concerned with rendering different, registered types of
  graph views.
* Added `GraphVizView`, which is a new graph view that uses
  [viz.js](https://github.com/mdaines/viz.js) to convert DOT files (from
  the API) into SVGs.
* Added `FilterableView`, which holds the common functionality of
  filtering for a graph view. `FilterableView` also handles the tracking
  of selections.
* Added `Filterable` component, which at the moment is entirely coupled
  to `FilterableView`. This will ideally be merely an augmentation on
  top of `ParentView` at some point.
* Added `JobDetailStatsView`, which displays 50th, 75th, 95th and 99th
  percentiles for each job's run time.
* Updated `docs/FAQ.md` with a solution to a problem that can be
  encountered when running jobs locally, with mesosMaster and mesosSlave
  started.
* Removed old dependency on rickshaw.
* Updated `JobDetailStatsView` to correctly show median value.