Adds custom animation to tooltips & popovers

[nanuclickity]

Implements #13622.

$('.logo').tooltip({
  animation: 'animated flipInX'
});

[cvrebert]

• The docs for the animation tooltip+popover parameter need to be updated too.
• This needs to implement a fallback so that explicitly passing animation: true / false will still work, for backward compatibility.

[cvrebert]

Also, this code still contains several hardcoded references to fade.

[mdo]

I'm still very interested in seeing this happen, but I don't think it can until v4 (since we're not doing a v3.3.0).

Thoughts @cvrebert and @nanuclickity?

[cvrebert]

Agreed.

[mdo]

Punted (and on the list).

[nanuclickity]

Agreed :)