Create own representations of Request and Response objects

[argos83]

Encapusulate WEBrick HTTPRequest and HTTPResponse objects into own representations.

The reasoning behind this:

• WEBRick representations are unnecessarily complex, there are a lots of different ways to achieve the same, and the naming and structure of requests vs responses attributes are inconsistent.
  • This should allow to decouple from WEBrick in the future without breaking the interface