Allow absolute path in Windows. ex) "C:\Documents and Settings\..."

[minodisk]

Referring to the 7052nd line :

return url.indexOf("://") === -1 && url.indexOf("?") === -1 &&
    url.indexOf('empty:') !== 0;

[jrburke]

Thanks for the pull request! Since r.js is a generated file, I did the change in the source file as part of this commit. I also generated an r.js snapshot for today in the dist/ directory if you want to start using the new version right away.