Remove tests that test redline values, fix a bug in aria test. Closes #594.
Re-add subset of tests from layout tests.
Fix a couple small styling bugs caused by the redline update in navbar.
Fix test output directory in unitTests project.
Migrate ItemContainer tests
Migrate ItemsManager tests.
 Task 782237:
 Wired handling for WinJS.Application's "backpressed" event into _Overlay family of WinJS.UI controls.
  Added Unit tests
  Refactored some code in the _Overlay light dismiss path to make readability and future modifications easier.
  Fixed a systemic Overlay issue where the element in some instances of _Overlay derivative classes still could not recieve programatic focus in non IE browsers. (div's require tabIndex -1).
  Refactored global _Overlay event handler handlers into a mechanism that allows for easy resets to aid unit test scenarios and provide better interoperability with Application.stop()
Merge branch 'master' into toolbar-branch