function argumentsToArray() {
    var len = arguments.length, args = new Array(len);
    for(var i = 0; i < len; i++) { args[i] = arguments[i]; }
    return args;
  }
Merges the specified observable sequences into one observable sequence by using the selector function whenever any of the observable sequences or Promises produces an element.
This can be in the form of an argument list of observables or an array.

@example
1 - obs = observable.combineLatest(obs1, obs2, obs3, function (o1, o2, o3) { return o1 + o2 + o3; });
2 - obs = observable.combineLatest([obs1, obs2, obs3], function (o1, o2, o3) { return o1 + o2 + o3; });
@returns {Observable} An observable sequence containing the result of combining elements of the sources using the specified result selector function.