Updated the icon and finally got the bitmap right

In case anybody is wondering, you need to use Pixelformer to save to the
correct type of BMP that will actually store alpha (transparency). I
even tried ImageMagick, but Pixelformer is the only thing that worked.
There is more info about images for the Windows Ribbon Framework here:
http://msdn.microsoft.com/en-us/library/dd316921.aspx