Update to Ember 1.5.0-beta.4, updates ember-data also

  * ember 1.5.0-beta.4
  * ember-data 1.0.0-beta.7
  * jquery 2.1.0
  * All tests pass: http://monosnap.com/image/Li8mF3s891Zkoo76yV46BbAqFjs77O
Merge pull request #886 from bantic/update-ember-1.5.0

Update to Ember 1.5.0, updates ember-data also