* Breaking change with new feature
The keyword arguments `next` and `previous` have been replaced by integers `1` and `-1`.
Multiple tags can also be cycled by using integers with absolute values greater than `1`.
* Additional new feature
Added `--skip-occupied` option that works in an analogous way to `--skip-empty`.
Thanks to Campbell Barton for help with keeping `--all-outputs` working when combined
with the `--skip` options.