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
Standardise the return value of `to_time`

This commit standardises the return value of `to_time` to an instance
of `Time` in the local system timezone, matching the Ruby core and
standard library behavior.

The default form for `String#to_time` has been changed from :utc to
:local but research seems to suggest the latter is the more common form.

Also fix an edge condition with `String#to_time` where the string has
a timezone offset in it and the mode is :local. e.g:

  # Before:
  >> "2000-01-01 00:00:00 -0500".to_time(:local)
  => 2000-01-01 05:00:00 -0500

  # After:
  >> "2000-01-01 00:00:00 -0500".to_time(:local)
  => 2000-01-01 00:00:00 -0500

Closes #2453
Use `DateTime.parse` inside `String#to_datetime`

Use the standard library's `DateTime.parse` because it's marginally
faster and supports partial date/time strings.

Benchmark:
       user     system      total        real
old  3.980000   0.000000   3.980000 (  3.987606)
new  3.640000   0.010000   3.650000 (  3.641342)
Added AR integration tests for form helpers
Merge pull request #9014 from virusman/form_helpers_ar_tests

AR integration tests for form helpers