In Browser Path Matching with Javascript

When debugging routes ,it can sometimes be difficult to understand exactly how the paths are matched. This PR adds a JS based path matching widget to the `/rails/info/routes` output. You can enter in a path, and it will tell you which of the routes that path matches, while preserving order (top match wins).

The matching widget in action:

![](http://f.cl.ly/items/3A2F0v2m3m1Z1p3P3O3k/path-match.gif)

Prior to this PR the only way to check matching paths is via mental math, or typing in a path in the url bar and seeing where it goes. This feature will be an invaluable debugging tool by dramatically decreasing the time needed to check a path match. 

ATP actionpack
Merge pull request #9001 from schneems/schneems/routes-path-js

In Browser Path Matching with Javascript