Allow other modules to implement additional url values before redirecting.

I have a scenario where the 301 is causing my paginated content to continuously fall back to the first page. This is because the paginated content is all one single node, devided by special characters and using the pagination module.

Example:
Old Url: http://www.mysite.com/article/1
New Url: http://www.mysite.com/node/1

When I attempt to do a http://www.mysite.com/article/1?page=2, the path redirect module finds the Old Url successfully, looks up the new url but does not respect the query string here since its not stored in DB. Locking down this to a hard DB look up really eliminates a lot of control the user should be able to have in the final url of the 301.

I've submitted a patch that allows the user to modify the $redirect array when path redirect is attempting to perform its 301. This way, developers can hook into this module and add query strings, make changes to the url, etc, as needed.