DropDownButton too tall in quirks mode (FF)

[bill]

See screenshot from themeTesterQuirk.html on FF (not IE, but FF):

This is on tundra theme (actually works correctly in claro).

The height is equal to the height of the ContentPane itself.

[bill]

The problem is this code in dijit.css:

.dijitButtonNode .dijitArrowButtonInner {
    ...
    height:100%;
    ...
}

The 100% is currently needed for TextBox widget arrows, but it's harmful for DropDownButton (and it isn't needed since vertical-align: middle does the centering for us there). I'll address this after #11034 is resolved.

[bill]

(In [22065]) Limit the height:100% setting on dijitArrowButtonInner to Spinner. It's not needed anywhere else because we use <table> or vertical-align:middle to center the arrow, and it was breaking DropDownButton in quirks mode. Fixes #11082, refs #11003