Fixes balloon tooltips

Balloon tooltips will show up above the hovered element if necessary.

Tooltips will be displayed below an element if they would be on screen (standard behavior).
![Standard](http://i1278.photobucket.com/albums/y519/InsertRandmNick/2013-04-09_2012_zps10669807.png "Standard")

But if they would be offscreen they will be displayed above.
![Anti-offscreen](http://i1278.photobucket.com/albums/y519/InsertRandmNick/2013-04-09_2012_001_zps839f00a0.png "Anti-offscreen")