Bump version 1.4.0

* NEW: You can now completly hide the content view and show it partially.
* DEPRECATED APIs:
	* `-setContentViewController:animated:completion:` replaced by  `-closeMenuBehindContentViewController:animated:completion:`
	* `-showContentViewControllerAnimated:completion:` replaced by `-closeMenuAnimated:completion:`
	* `-showMenuAnimated:completion:` replaced by `-openMenuAnimated:completion:`