improve method matching for better content negotiation

[jjn1056]

[abraxxa]

I'm thinking about enabling the dispatcher to match actions based on all request attributes regardless of what they are like the Radiator Radius server, which is also written in Perl, does it.
As the request is already an object that's extensible with roles like browser detection it could be something generic as matching request attributes.

[jjn1056]

I think we'd need to say Method and ACCEPT stuff needs to be the last action in the chain to do this right..

[jjn1056]

and maybe some updates to the action class to give the dispatcher some way to sort when more than one action matches a route.