Progressbar update
Progressbar update

* Add support for progressbar in imap_unordered
* The progressbar is now optional for both map and imap_unordered
  It is disactivated via CondorPool(..., progressbar=False)
  [progressbar=True by default]
* Define a dummy ProgressBar object if the ProgressBar module is
  not available.

fsteinmetz/runlib