Adding "run-clean" target. This will create a new "temp" preferences/…

…profile dump. The preferences will be cleared on every start.

Two command-line arguments have been added:
--alternate-prefs PREFSNAME
 This uses an alternate preferences set, and the ~/.replicatorg/alternate/PREFSNAME directory for files.
--clear-prefs
 This will clear the chosen preferences set on startup.

NB: clearing preferences with no alternate prefs selected will clear *all* your preferences sets.