Cappuccino Cappuccino

Improve toolbar item layout.

The height of all items is determined by the tallest item, like in Cocoa. But unlike Cocoa our toolbar is presently fixed height so in order to make this look well for small or large items, the whole row of items is now vertically centred, making the allocation of margin above and below automatic.

Furthermore if a toolbar item has a small view or a small icon, it is now centred within the available space above the label. For example, for a tiny icon in one item next to a normal size icon the tiny icon would be centre aligned with the larger icon.
https://github.com/cappuccino/cappuccino/commit/3bc18490418b6bd051b...