Adds the ability to specify the view class used by the outlet Handlebars helper

Previous to this change, the view class used was always an "OutletView" (Metamorph extension of ContainerView).  This change allows the class to be set while still defaulting to the OutletView
Simplify not-null-or-undefined checks

Save ALL the bytes!

`a != null` is what the CoffeeScript compiler emits for `a?` -- it's a
cute idiom, and we use it in several places already.
- Deactivate route handlers before destroying container in App.reset()
- Upgrade router.js micro-framework
Merge pull request #2698 from joliss/null-checks

Simplify not-null-or-undefined checks
Merge pull request #2650 from mhelabs/reset-router

Deactivate route handlers before destroying container in App.reset()
Revert "Revert "Replace Ember.RunLoop with Backburner.js""

This reverts commit 43e25d03fb02313c990326408286e58ceced3443.

Conflicts:

	packages/ember-application/lib/system/application.js
Update Backburner.js
Merge pull request #2310 from robharper/feature/outlet-viewclasses

Ability to specify the view class used by the outlet Handlebars helper
Set actions as the default run loop queue
Merge pull request #2705 from teddyzeenny/default-queue

Set actions as the default run loop queue
Use helper function to remove duplication
Remove unused variable
Merge pull request #2707 from tricknotes/use-helper-function

Use helper function