Finally commit the testing stuff I have been with this week. Could be considered...

Finally commit the testing stuff I have been with this week. Could be considered a continuation of r79411.
Mixture of the NewParserTests.php with old code present in MediaWikiParserTest.php, reverting r79184 (revert of a revert...) and even eval().
Using the iterator as dataProvider, but defering the insertion of articles, as the dataprovider is processed on load, before switching dbs.
Each parser test appear now as a phpunit test. This means that by adding 683 tests (partly from extensions) we now surpass two thousand tests.
The downside of that is that they become painfully slow.
Initialise $wgHooks to $wgHooks, not to array() (r82499) as otherwise we lose ParserFirstCallInit registrations.
There's no attempt to support extensions registering to $wgParser instead of using ParserFirstCallInit properly (Cite falls in this category).