Create multiple actions convenience function

[spoike]

Add to the Reflux API a way to easily create multiple actions to an object with an array of names as parameter. Example:

var Action = createActions([
    "activateGem",
    "deactivateGem",
    "openPopup",
    "closePopup"
  ]);

console.log(Action);
// Should output something like this:
// {
//     activateGem: {Action},
//     deactivateGem: {Action},
//     openPopup: {Action},
//     closePopup: {Action},
// }