Add friendable users endpoint

[#22]
Add Friendable User ember model

[#22]
Add a friendable users controller; embed it in the friends route

Also add a little crappy placeholder friendable users template.

[#22]
Add typeahead library

[#22]
Add Autocomplete component + stylin'

[#22]
Add autocomplete field to friendable users page

[#22]
Use the right key event so we capture backspaces

[#22]
Clean up autocomplete component + friendable users controller

- Make it leverage events and properties, rather than a bunch of custom
  functions and stuff
- Fix clearing out the old user if the query has changed
- Disable the + button if there's no user selected

[#22]
Clarify some property names

[#22]
Add an endpoint for creating a new friend

[#22]
Actually call _super() correctly in friends route

I was calling super(), but not passing the arguments, which meant that
the model in the friends route was always null. #whoops

[#22]
Make the + button ask the API to create a new friend

[#22]
Clear out all the data on logout
Now we shouldn't have to worry about spooky crufty data anymore.

[#22]
Center friends

[#22]
Make friendships added by the API mutual

[#22]
Change header on friends page

[#22]
Unpend + pass friends spec

My goodness, what a pain in the butt this was. Testing Ember with
Capybara seems like a suboptimal approach.
Revert "Unpend + pass friends spec"

This reverts commit c09e0cc9281aec1a1b6650733794f9e02f18284c.
Merge pull request #36 from gschorkopf/killpack/new-friends

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