Settings.DIR_COMMONTEMPDIR directories should be emptied upon startup

The bitarchive-servers should empty their Settings.DIR_COMMONTEMPDIR in the
constructor
If the app does not clean up nicely the tempdir could run full - for the
bitarchive-machines this will cause e.g. batch-jobs to fail
The temp-dir is checked / created in BitarchiveServer.java (CTOR)
Might want to check if other apps should do the same
NOTE: This bug is originally from Bugzilla bug_id=431.
This bug was previously assigned to Unassigned.