Proposal: Removing wsgiorg.routing_args and paste.urlvars support

[digitalresistor]

While working on WebOb 2.0 in I came across support that is in webob.request.Request for urlvars and urlargs, this seems to be based upon the wsgiorg.routing_args "standard" and paste.urlvars which is a Paste specific extension.

I am not sure how heavily used these standards are, nor do I know if they have been ported to run on Py3.

I am considering removing them from WebOb, or at least moving them out of the base request into a mixin that a user could opt-in to.