code: function rejected(val) {
      var ret = new Promise();
      when(val).chain(ret.errback, ret.errback);
      return ret.promise();
  }
docs: Creates a new {@link comb.Promise} that is rejected with the given value.
  
  ```
  comb.resolved(new Error("error!")).chain(null, function(err){
  console.error(err.stack);
  });
  ```
  
  If you give it a promise it will wait for the promise to resolve or error but with reject either way.
  
  ```
  comb.resolved(new comb.Promise().callback(1)).chain(null, function(err){
  //err === 1
  });
  ```
  
  @param val - val to reject with
  @returns {comb.Promise} a rejected promise with the specified value.
  @memberOf comb
  @static