Redirect Route strict_slash fails on POST

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Map a URL using Redirect Route and set strict_slash=True

RedirectRoute("/some/address", MyHandler, name="handler", strict_slash=True)

2. Have the URL map to a handler that has post implemented

class MyHandler:
    def post(self):
         #stuff here

3. Make a REST POST request to the URL with a trailing slash

What is the expected output? What do you see instead?
I'd expect the POST call to reach the post method. Instead I get a 405 error, 
which I don't see if I removed the trailing slash. I also don't see this if the 
HTTP verb is GET. 

What version of the product are you using? On what operating system?
webapp2 2.5.1, MAC OS X 10.8.3

Please provide any additional information below.
The behavior also happens when the URL mapping has a trailing slash and the 
POST request does not. 

Original issue reported on code.google.com by an...@striiv.com on 7 Oct 2014 at 11:58