A bunch of JS fixes:

* One new i18n message
* Added jquery.ui.dialog as a dependency instead of hackily loading a custom build of jQuery (which doesn't even work outside wikiHow, since that particular reference and jQuery UI build exist only on wH)
* Fixed various URLs in the JS file to use mw.util.getUrl() instead of assuming that everyone has a null script path (as wikiHow does)
* Got rid of jQuery.live()

Change-Id: I665d3cfb457960cc9f0bfd72ca8102cd68326f46