Patch Testers sought, significantly faster named routes

http://dev.rubyonrails.org/ticket/9450

The detailed description is in the ticket, but in my testing this
patch makes named route generation between 6x and 20x faster. For
applications with a large number of routes, odds are it's even faster.

I'm seeking testers with a large number of named routes, who can
really put this optimisation through its paces. We're looking for
anything which breaks.

So far the only case I've found is that customer_url("//") will
currently raise a RoutingError, but with this patch it will generate
/customers/%2F%2F.

The detailed description is in the ticket, but in my testing this
patch makes named route generation between 6x and 20x faster. For
applications with a large number of routes, odds are it's even faster.

I'm seeking testers with a large number of named routes, who can
really put this optimisation through its paces. We're looking for
anything which breaks.

So far I've fixed the two breakages that have been reported, and
extended the optimisation code to cater for the additional arguments
syntax that ian provided in [7411].

If you're doing something 'different' with named routes, or just using
a lot of them, I'd really appreciate some comments on the patch.