Replace wrapper hack with simple inheritance

[jkrems]

This changes the way that gofer works internally while exposing the same interface. It also allows a new, simpler way of using gofer:

// ES6
import { Gofer, registerEndpoints } from 'gofer';

class Github extends Gofer {
}
// Because ES6 classes do not support value properties...
Github.prototype.serviceName = 'github';
Github.prototype.serviceVersion = '1.3.2';

// or just: Github.prototype.registerEndpoints({ ... })
registerEndpoints(Github, {
  emoji: function(request) { /* ... */ }
});

# coffee-script
{ Gofer } = require 'gofer'

class Github extends Gofer
  serviceName: 'github'
  serviceVersion: '1.3.2'

Github::registerEndpoints {
  emoji: (request) -> # ...
}

[jkrems]

This could be removed when switching to POCS*.

[*] Plain old coffee-script, as opposed to CSR/redux.

[abloom]

This seems reasonable. The diff is a little hard to read but I think it makes sense. The only oddity I noticed was the use of both Object.prototype.something and Object::something. Do you mind unifying on a single style?

[jkrems]

Went with all Object::something, updated.

[abloom]

so fresh and so clean

[jkrems]

v1.2.0

[abloom]

Can you open a new PR to update API.doc, README and examples/github.js?