Fixed URL_DETECTOR pattern for querystring/hash

The old URL_DETERCTOR did not match url strings with querystring/hashes
in them. It limited the querystring/hash to only contain `?`, `#`, `\w`.
That caused url strings like `../font/fontawesome-webfont.eot?v=3.0.0`
(from font-awesome project) to be rejected. As a result, Django-pipeline
would not calculate new relative path for the such resources (font file in
this example), hence breaking the resulting css file. The new pattern allows
any characters after the extension which solves this issue.