[Suggestion] All buttons should have their quick key easily visible

I think everyone quickly noticed how the QWER keys are nicely labelled to show that they map to your skills. This is great UI feed back.

All buttons that have a quick key should be this way.  For example, to bring up your skills tree, you can press the 'k' key, I believe, but this button is not labelled like the skill keys are.  It it were, I would be more likely to start using the 'k' key to bring up this window.

At the very least, the quick key should be shown via a tool tip. This mechanism can be used in places where actually embedding the quick key right into the button's icon adds too much clutter or makes the button less readable.