Tooltips are now UIWidget. This allows them to contain non-textual elements, and to be extended (via wrapping in a Layout and added further elements to that layout). Simple methods for setting and binding strings for tooltips have been retained.

.ui files now support a simplified declaration of UILabels as simple strings. Obviously allows for the tooltip declaration, but can also be used anywhere a label may be desired. See the videoMenuScreen.ui for an example.
Merge pull request #1041 from immortius/develop-tooltips

Tooltip Widgets