Fix issue 1513: YUI violates Content-Security-Policy

Simple change to remove use of 'eval' like code from yui.js in order to satisfy any strict Content-Security-Policy headers.

Ran complete unit tests with YETI on my OSX Version 10.8.2 with Chrome Version 31.0.1650.63, Safari Version 6.0.2 (8536.26.17), and Firefox Version: 17.