Use specified versions in the RunconfigToDistribution task (take 2)

The `RunconfigToDistributionTask` did not use the versions supplied for non-snapshot bundles, but always defaulted to the latest version available in any repository. This PR does not only fix this, but also add options to toggle some of the behaviour in this task, such as verbosity of logging and whether or not the output directory should be cleaned prior to copying all JARs, making this task a little more friendly for the casual user.

(resubmit on correct branch, see also #397).