ukopp 3.5

+ GUI revised: retention specs for old file versions on the
   backup media are easier to specify and more conventional.
   Other changes to the GUI were done to make it easier to use.
   Changes to the job file format will require minor re-editing.
+ Better detection of conflicts bewteen user intent and actual
   status of target devices and directories.
+ Do auto unmount at end of job only if auto mount was done at start.
+ Do auto deletion of mount point directory only if created by ukopp.
+ Bugfix: include/exclude filespec containing blanks did not work.