NewParserTest.php can now work independently

NewParserTest.php can now work independently

PHPUnit load class according to their order on the filesystem I guess.
On the cruisecontrol host, it first load NewParserTest.php and run
the test then load MediaWikiParserTest.php which run the tests too!

On my host the order is reversed, and NewParserTest.php is never run
for a reason I have not investigated.

Anyway, deleting the MediaWikiParserTest.php is harmless since it is
redundant with NewParserTest.php

(should fix cruise control)