Add headers and remote IP

[marshallswain]

This is too common of a request to not be next on the list. There are a lot of headers that match between the transports: https://gist.github.com/marshallswain/b775c7b6d7a9b2429b0eb6fe669a2bfd

Currently the auth plugin has the expose-headers middleware, but I think we should move it here and and the remote IP address on the feathers object, as well.

app.use(function (req, res, next) {
  req.feathers.headers = req.headers;
  req.feathers.ip = req.ip;
  next();
});