Added WagtailTestCase class with a couple of useful methods
Added LOGIN_REDIRECT_URL to runtests.py settings
Use new WagtailTestCase class for checking redirect URLs in account management tests
Return user object from login method
Use WagtailTestCase class in admin page views tests
Made WagtailTestCase a mixin and renamed to WagtailTestUtils.
Fixed missing import
Added template used assertions into many tests
Added URL assertions to tests which test redirecting
Always use login method from WagtailTestUtils
Merge branch 'master' into tests-changes
Merge branch 'tests-changes' into issue-25
Added test to check that wagtailadmin behaves correctly when LOGIN_URL is not set