Pass responseHandler to the error interceptor - fixes #528

When using the errorInterceptor there is no way to continue the request _as if nothing had happened_. For that reason I created this PR.

````javascript
Restangular.setErrorInterceptor(function(response, deferred, responseHandler) {
    // The interceptor now receives a third argument

    $http(response.config).then(responseHandler, deferred.reject);
    return false;
}
````

Thanks and keep up the good work :+1: