Fix EZP-21274: Re update YUI 3.12.0 due to inconsistencies

The version present in ezjcore has a few errors as described in the https://jira.ez.no/browse/EZP-21274 issue. The problem is that the file isn't the same that is present at http://yui.yahooapis.com/3.12.0/build/yui/yui-min.js.