This patch enables all of the features for the Flavors panel to use Angular but
disables it, so that it is easy to switch on/off.
Note that we add integration test switches since it can't read the Django
conf.
Note that I changed the common tests to allow for testing of api calls that
don't produce error toasts, because we needed better branch coverage, and
the deleteFlavor api wasn't fully branch-tested.
Change-Id: I92b1b57bd486e5eb87179cb8d44b7551e9de2e0f
Partially-Implements: blueprint ng-flavors