Display all blue bars above all red boxes

[garrettgman]

When plotting the ghost boxes of previous boxplots, all of the blue bars should be plotted on top of all of the red boxes to reduce visual interference

[garrettgman]

I changed the ghostGrob to call ghostboxdotGrobs which draw ghostbxpGrobs. This allows the blue and red parts of the ghosts to be plotted separately. onesampBootGUI is adjusted to work with these, but the other demo's still need to be adjusted.

One problem is that ghostGrob calls up different types of sub grobs depending on its arguments. I'd like to change this once I figure out if it is necessary anywhere (it doesn't seem to be). If it is necessary, it would seem more useful to have a ghosting function that you could just apply to a predefined grob. The function could have methods for the different grob classes.