Add backbone-on-rails gem and scaffold for location model
Lighten the Add-to-trip button to be more easily readable
Removed Backbone alert.
Turn Add to trip buttons into ajax
Move all the js code into a class
Further break JS into classes.
Add Backbone models for the Locations in the Trip.

When adding a Location to the Trip, the server now replies with a JSON array of
the Trip Locations. Those are then put into new Backbone models and rendered to
the Trip list with a eco view template.

The template is very bare-bones right now and needs a lot of work to make it
appear like the server-generated one, but it's already way faster than the old
way (which was to update the Trip list by reloading it with a second AJAX call
that returned the HTML).
Replace eco template with haml
Replicate part of the trip location HAML in the HAMLC.

This allows the JS to write trip locations closer to what's written on the
server side. There's still quite a bit missing, though, including URLs, and
references to the Trip object itself, as well as the help dialogs that require a
reference to the Locations object.
remove some (AFAIK) unnecessary instances of =>
Move Trip json rendering to model and simplify
Pass full locations list on to Backbone view
Refactor Backbone view to use a Trip view instead of Locations.

That's what we're really displaying, anyway, a Trip, not just a collection of
Locations.

To complete it, this will require the model on the server to store distance in
the DB so it can be easily serialized into JSON and passed to the Backbone
model. It's a good idea anyway.

The old Location model/collection/view is still there, but should be removed at
some point unless it's used for something else.
Remove debug logging for add-button
Add AJAX functionality to Remove buttons as well
Add AJAX functionality to Clear Trip button
Set up ajax remove and clear on load as well as after an add
Display all help boxes properly in trip list.

This required passing a list of all locations down to the Backbone model.
Pass trip distance as JSON when returning Trip as AJAX
Add meters_to_miles method in Backbone view so distance shows correctly.