Stop using extended method

I used `Ember.String.fmt` instead of `String#fmt`.
Because the latter may be undefined.
Fix failing test

This package couldn't be required from test.
Merge pull request #2235 from tricknotes/fix-failing-test

Fix failing test
Better HistoryLocation popstate handling - Fixes #2234
Fix 'rake test[built]' task
Merge pull request #2233 from tricknotes/stop-using-ext-method

Stop using extended method
Added Campfire notifications to Travis
Remove apparently inactive travis upload hook
Only notify Campfire when build status changes
Updated {{outlet}} documentation to reflect rc1 API for issue #2143
Better warning for missing initializers - Fixes #1906
semicolons
Added ability to customize generated controllers and routes
Minor docs cleanup
Fix ArrayProxy arrangedObject handling - Fixes #2120, #2138
Update accessors.js

typo should be 'If we are on a platform that supports accessors we can use those' 
instead of 'If we are on a platform that supports accessors we can get use those.'
Merge pull request #2247 from rmossuk/patch-1

Update accessors.js typo in comments
Merge pull request #2243 from rafshar/#2143-outlet-docs

Updated {{outlet}} documentation to reflect rc1 API for issue #2143
Improve Ember.Array slice implementation

Add support for negative index arguments.
Added length property to Ember.Map