A tricky one: $scope.$digest vs $scope.$apply

$digest only digests the current scope while $apply digests everythign starting
from the $rootScope. Because of this, the change to $scope.isAuthenticated was
not seen.

I can’t think of a good way to test this without getting a bit too intimate
with the production code, so I will capture this with a UI test.
Web UI tests: small reorganisation

Separated tests that seemed to be unrelated.
Start page: show a message upon successful authentication
Registration form test: use default time out

With 100ms it seems not to make it in time sometiems. I’ll try this and see how
it works.
InMemoryDataService

For the UI tests FirebaseDataService would be too slow.
Firebase tests: stub out watchOnlineStatus()

PhantomJS’s navigator is never onLine and because of that Firebase client
always switches to offline mode, which is not what I want.
make jshint: also lint TEST_HELPERS
Chai helper: containsText: refactor and improve failure message
Use in-memory data and authentication services in test mode

This will make it possible to have fast UI tests.