fix(viewLifecycle): move event emit after transition cleanup

[mlynch]

Right now view lifecycle events can fire before the transition is fully cleaned up, meaning our past view can be in a leaving state instead of cached when the new view's $ionicView.enter is triggered.

This fixes #2939 where this code would not correctly clear the last view because it is marked leaving rather than cached in the navViewController.clearCache function:

controller('MyCtrl', function() {
  $scope.$on('$ionicView.enter' function() {
    $ionicHistory.clearCached();
  });
});

The fix was to move the event emit to the bottom of transitionCompleted in viewSwitcher.js

[mlynch]

Yea some of the tests are failing and need to be fixed

[mlynch]

Landed 06ef682