[Core JS] More fixing of global config variable usage

[Core JS] More fixing of global config variable usage
* mw.config is the new way, and global config variable lookups are deprecated

* Based on two phase3-wide quick searches:
-- of " wg": http://toolserver.org/~krinkle/wikimedia-svn-search/view.php?id=321&hash=81700bf7486e4fee3b7bc1f83eb9eba6
-- of "!wg": http://toolserver.org/~krinkle/wikimedia-svn-search/view.php?id=327&hash=47c9d54a7a1d5d58a724dd834585f40d

Related changes:
* Changed some php comments mentioning "wg" variables to include the dollar sign, and a typo when the wf function prefix was meant.
* Removed TODO comment in wikibits.js and made it use the JS equivalent of wfUrlencode, which we have now, mw.util.wikiUrlencode
* SpecialUpload.php: use OutputPage::addJsConfigVars instead of creating a new script tag through OutputPage::addScript(Skin::makeVariablesScript(..))
* Renamed wgUploadSetup in upload.js and made it local. Not used anywhere in ./trunk/phase3 and ./trunk/extensions
* Fix OutputPage::addJsConfigVars so that it can actually be called with an array instead of two arguments for key/value
* Some minor whitespace/convention stuff around the same line