Feature request: annotation_scale: number of ticks and maximum value

[modche]

Hi,
nice package, using annotation_scale() really often for maps in ggplot2.
Would be nice to set the number of breaks in the scale and/or the maximum. So I get 3 ticks (à 20 km) with a maximum of 60 km, but I want 2 ticks and max=100km.
Michael