Cycle through brushes panel items via keyboard

[ladlon]

It would be cool to be able to step up/down through the various brush items in the Brushes panel using a keyboard shortcut, rather than having to move the pointer over to the panel and clicking on them (which, I find, is often a bit finicky as it is... sometimes requiring two clicks to get the selection to register).  Being able to step through using the keyboard would allow very rapid jumping through multiple brushes, painting some strokes, changing the brush, painting some strokes, etc.