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 'master' into tests-changes

Conflicts:
	wagtail/wagtailembeds/tests.py
	wagtail/wagtailsnippets/tests.py
Improvements to page chooser tests
Minor PEP8 fix
Merge pull request #281 from kaedroho/tests-changes

Tests changes