Updating mw.util.test.js + fixing minor bugs that were discovered through it

Updating mw.util.test.js + fixing minor bugs that were discovered through it
Updating mw.util.test.js
* Adding tests for modules now loaded by default [[RL/DM]]. Still not all of them, but it's getting there
* Changing order to either alphabetical order or order from source code (instead of random or chronological)
* adding addHead() function
* Fixing a bug caused by addHead() with  (which selected all rows instead of rows that contain actual tests) - also removed the need for the "+1" adjustment later on in the code (which was needed since  contained the first row with the column headings)
Fixed bugs that were found through testing:
* No title attribute was set for skins without portlets. (it was after the portlet-presence check).
  Now older skins get the title attribute as well.
* Modern's article-container ('#mw_contentholder') is added to the definition for mw.util. in mw.util.init()