Update jquery.jgrowl.js to 1.2.12; fixes beforeClose param is not working

reported on the t5 mailinglist:
http://apache-tapestry-mailing-list-archives.1045711.n5.nabble.com/jquery-jgrowl-params-not-working-td5722275.html

reported in t5-jquery google group:
https://groups.google.com/forum/?hl=de#!topic/tapestry5-jquery/mNg_H4JkhpY
Merge pull request #304 from daveyx/master

Update jquery.jgrowl.js to 1.2.12; fixes beforeClose param is not working