Closes #10363
In the original mtvservices:embedded test case, config.xml is still used
to get the feed URL. Some other examples, including test_Generic_40
(http://www.vulture.com/2016/06/new-key-peele-sketches-released.html),
and the video mentioned in #10363, use another endpoint to get the feed
URL. The 'index.html' approach works for the original test case, too. So
I didn't keep the old approach.
· Import from compat what comes from compat. Yes, some names are available in utils too, but that's an implementation detail.
· Use _match_id consistently whenever possible
· Fix some outdated tests
· Use consistent valid URL (always match the whole protocol, no ^ at start required)
· Use modern test definitions
