clean up Html::inlineScript usage

clean up Html::inlineScript usage
* ResourceLoader::makeLoaderConditionalScript:
-- window.mediaWiki -> window.mw; Not just because it's shorter but because that's the variable that is actually being used inside the script.
* ProtectionForm::buildCleanupScript
-- Use a single quote string and no new line
-- Use ResourceLoader::makeLoaderConditionalScript instead of duplicating this logic everywhere
* ProtectionForm::buildCleanupScript:
-- Use Xml::encodeJsCall to render javascript code
-- Use ResourceLoader::makeLoaderConditionalScript
-- Fix bug 31230 by using the new OutputPage->addJsConfigVars( r98374 )
(had to use $wgOut for now since there wasn't an obvious route to a context that I could find here (Article has context, but ProtectionForm::__construct takes any WikiPage, not just Article)
* EditPage::getEditToolbar:
-- Use Xml::encodeJsCall
-- Use ResourceLoader::makeLoaderConditionalScript

Fixes:
* (bug 31230) ProtectionForm should set wgCascadeableLevels in mw.confg instead of globally