Adds middleware plugins to Farscape


Adds middleware plugins to farscape so other gems can add crazy middleware to the requests
Wonder if this might not be better as a module so someone could either extend middleware class or create a custom middleware class that does this so one could just extend another middleware and include this.

Frankly, I think an explicit approach with a configuration block/configuration builder that you can use to explicitly add middleware is a better long term solution than this which is magic.