/**
   * Invokes the specified function asynchronously on the specified scheduler, surfacing the result through an observable sequence.
   *
   * @example
   * var res = Rx.Observable.start(function () { console.log('hello'); });
   * var res = Rx.Observable.start(function () { console.log('hello'); }, Rx.Scheduler.timeout);
   * var res = Rx.Observable.start(function () { this.log('hello'); }, Rx.Scheduler.timeout, console);
   *
   * @param {Function} func Function to run asynchronously.
   * @param {Scheduler} [scheduler]  Scheduler to run the function on. If not specified, defaults to Scheduler.timeout.
   * @param [context]  The context for the func parameter to be executed.  If not specified, defaults to undefined.
   * @returns {Observable} An observable sequence exposing the function's result value, or an exception.
   *
   * Remarks
   * * The function is called immediately, not during the subscription of the resulting sequence.
   * * Multiple subscriptions to the resulting sequence can observe the function's result.
   */
  Observable.start = function (func, context, scheduler) {
    return observableToAsync(func, context, scheduler)();
  };