Button: unequal height of buttons

[bill]

See themeTester.html.

Even if I change the test to use the same icon for all the buttons, the DropDownButton and !Button are taller than the ComboButton on IE. It's a slight difference, maybe 3px:

(Note that the plus icon and note icon seem to be a different size... that's just a test file problem but please fix that too... however the main point of this ticket is that even when the icon is the same, the button heights are different.)

[bill]

screenshot of height-mismatched buttons

[bill]

As per email thread, this seems to be because ComboButton doesn't contain a <button> node. To quote Doug:

I think ComboButton should have a table with a button node on the left and a non-button on the right. I couldn't get this to size correctly but that was a long time ago. Maybe a fresh try by Nikolai will be successful.