Database support for panes to be configured.

There was a 4 month gap between the start and finish of this feature, so
I probably jacked it up a little reacquainting myself with everything.
Minor test cleanup.
Update Rails.
Update fakeredis.
Bundle update.
Huge amount of changes around admin area.

Well, first...  I broke the tests.  I can't figure out why Poltergeist
is having a problem, because in the browser it's golden.

  * Nuked the admin tests and the admin views and made a board list in
    Ember.
  * Got rid of Settings.
Allow moving from board to board list.
Use Bourbon Neat for the grid.
Update bootstrap.
Replace busted Settings in the navbar.

With useless Add/Edit slide icons.
Add Board creation form.
Styling on new board form.
Basically working with Ember pre4, except where it's broke.
Bundle update.
Test shenanigans.

Found an Ember issue here that is responsible for some integration test
failures: https://github.com/emberjs/ember.js/pull/1571
Manually patching the framework sucks, but it's better than not having
integration tests!

Upgraded Capybara and needed to move integration tests to spec/requests.
Fix board polling buildup while not visible.
Some fixes for newer Ember Data.

Added a slide in the database and all hell broke loose.  New ember-data
would prefer embedding the slide ids and sideloading records, it
appears.  Also realized that the RESTAdapter now auto-translates
attribute_name to attributeName, so that's nice.
Terrible slide creation interface.
Refactoring to follow ember best practices.

Got my template paths sorted out so that they could be inferred, which
allowed me to delete most of the views.  A few other minor things.
Use Ember.computed in place of parens.