Function: createRouteFactories
This is called by the constructor of <APIAdapter> and is heavily inspired by
the fancy Express.JS Application API.

It creates a function for each available HTTP method and makes it available
through the <APIAdapter> itself.

These functions then can be used to create an APIAdapter route.

Example:
> apiAdapter.get('/myroute', function myCallback(success) { success(); });
> apiAdapter.post('/myroute', function myCallback(success) { success(); });
> // any HTTP verb :)

DELETE Routes:
Since "delete" is a reserved word in JavaScript, you can use "del" as an
alias when creating a DELETE route.
function createRouteFactories() {
	var self = this;

	_.each(httpMethods, function(httpMethod) {
		self[httpMethod] = function(url, callback) {
			addRoute.call(self, httpMethod, url, callback);
		};
	});

	if(_.has(self, 'delete')) {
		self.del = self['delete'];
	}
}