Previously when setting an action's icon we would only change the bitmap
stored by the action. This patch adds logic to propagate that change to
toolbar buttons as well as window menus.
This fixes an issue in SoundPlayer that would cause the play button not
to reflect the play state.
With this change you can now set the theme and background color at the
same time in the Display Settings. Before if both were changed
before hitting 'apply' the theme background color would overwrite
the custom background.
