tests now extends MediaWikiTestCase

The test suite used some awkard way to detect MediaWiki and load class
it depends on.  The MediaWikiTestCase takes care of all of that already.

* Added an assert to make sure the spoofedname was actually legal
  unicode instead of blindly ignoring any error.
* Described the provider values.
* Split long lines

Change-Id: Ideb31dd8ee3b2ce59f9f9fe69e21c90f2cf2c06b