0.2.6: uses logging for presenting end-user information.
0.2.6: Pass a log object to the tasks.

This allows tasks to provide helpful output to the user, while it also gives
some tasks the ability to change how the logging is presented. For instance, a
task could just modify the `log` object at configuration phase to make
important notifications be presented through growl or inotify.

The `help` task was updated to use logging rather than throwing errors.

--HG--
extra : amend_source : 53bc136d4ce760b01886930771f45fb369c366b4