tweak variable name and tidy
experiment with conditional modification abstraction
Don't show prune progress - too much noise

For 'reasonable' use, you should never have to prune - this is just
for those users that like to do multiple runs against the same,
ever-diminishing repo.

There's already too much information for the casual user to absorb, so
cut the noise a litte.
tidy and use Scala 2.10 'wrapAsScala|Java' conversions

http://comments.gmane.org/gmane.comp.lang.scala.sips/550