[fix] normalize path on windows

Hi, had small issue about adding resources to my tests. 
OS: Windows 7
Reproduce:
<ul>
<li>Add script - <tt>%project%/test/letters/a/a.small.js</tt></li>
<li>Add resource template to <tt>buster.js</tt>:<tt> "test/**/*.js"</tt> </li>
<li>While testing, embed script tag referencing to that script <tt>%contextPath%/test/letters/a/a.small.js</tt>, and you receive - 404</li>
</ul>
That is due to path normalization on node.js under windows [backslashes], ResourceSet will contain: 
<code>"%contextPath%/test/letters<b>\\</b>a<b>\\</b>a.small.js"</code>. So that resource would be not matched by the virtualization.

Hier is quick, and also dirty fix of that problem - but hope, it will be helpful. <i>Thanks for busterjs - great job.</i>