Updated Bundler.cs VirtualPathUtility.ToAbsolute

If a website is not sitting in the root folder of the server the URLs are not made relative correctly.
Eg
WebApp sits under /MyProject/

Renderer Urls look like: /MyProjectscripts/jquery.js
Urls must look like: /MyProject/scripts/jquery.js
Merge pull request #60 from peitor/patch-1

Updated Bundler.cs VirtualPathUtility.ToAbsolute