Fix Special:JavaScriptTest

* Updated jquery.qunit.js (so asserts can be extended)
* Updated mediawiki.Uri.js (so mw.Uri can be initialized without any params)
* Updated ResourceLoaderContext.php (so many modules can be loaded at the same time)
* Created example test file
Fix Special:JavaScriptTest

* Updated jquery.qunit.js (so asserts can be extended)
* Updated mediawiki.Uri.js (so mw.Uri can be initialized without any params)
* Updated ResourceLoaderContext.php (so many modules can be loaded at the same time)
* Created example test file
Merge pull request #1449 from Wikia/VE-309

VE-309: Fix Special:JavaScriptTest