Improve tooltip logic

- Once a tooltip is visible, quickly moving
  the cursor to another tool button should
  immediately hide the current tooltip and
  show the new one, with no delay. This improves
  ui scannability.

- When a tooltip is visible and the button
  is clicked, the tooltip should hide.

- If a tooltip is waiting to show and the button
  is clicked, the tooltip should not show.

These seem like small details, but they add up.
Make tooltips match the color of the button
Update appcache revision