request methods, and handles head and options automatially
adds rack as a dependency
requires response class
new errors

- descend from HTTPError to rescue them in the Server
- adds http_status_code method to HTTPError classes, for use by the Server
require new error classes
adds methods to map symbols to their HTTP equivalent and vice versa
uses Rack::Response to return the results of the Resource#response_handler

as well as begin to bring Hypermedia semantics into the pricture
ignore config.ru from repos and adds support for .gitkeep