New features (hint--hide)

Hi my friend.

Sorry that I put the request here but in request I didn't found how to put files.

I am using your module with javascript, when a button is pressed, them the tooltip is showed, after a time it hide again.

So I implement 2 new clases:
hint--hide (allways hide if don't have the class hint--in)
hint--in (similar to hint--always but with the efects)

So if you have the element with hint--hide you can put with javascript the class hint--in to show it and them to hide it again you can remove the class.

I wish it can help to the project, you can download the finished file here:
[hint.txt](https://github.com/chinchang/hint.css/files/230912/hint.txt)

Bye =)!