Update lists before adding/subtracting/intersecting them

When you do list operations, i.e. adding/subtracting/intersecting other lists with a "parent" list, SmartPlaylist currently takes the last saved titles from them.

With the next version of SmartPlaylist there will be a new behaviour:
Lists will be automatically updated (loaded and saved) before adding/subtracting/intersecting them to/from/with the parent list. Like that you no longer need to go and reload them one by one before using them in a parent list.

Some hints about list operations:

• If you do not specify any search rules SmartPlaylist will load ALL songs you have in your media library. Adding other lists to that will have no effect, of course.
• If you want to have a list, say "A", just to add/subtract/intersect other lists, you have to specify an "impossible" rule like "Genre xyz" in "A" - this gives you an empty list to which you can add other lists
• SmartPlaylist always first adds the "+" (add) lists, then subtracts the "-" (subtract) lists and finally intersects this result with the "=" (intersect) lists

Some more afterthoughts ...

Thought I could improve (change, anyway) a few things in SmartPlaylist for the next version 9.4:

Now there are 26 smart playlists (SmartPlaylist A-Z) at your disposition:

• Open list overview with all 26 SmartPlaylists to pick from ("≔")
• Jump back to the now playing SmartPlaylist ("▷")
• Scroll up/down to previous/next SmartPlaylist ("^" / "v")

All 26 smart playlists can be used in the list operations Add / Subtract / Intersect (Was called "Fusion" before - Please re-define your operations with the new pick-list)

There is now a play button in the Detail view (long press for play/pause still works). "Add./Rem." and "Same" now appear in the info list.

New feature in v4.12: Fusion of different smart playlists into one

Until now you could only add / subtract / intersect the previous results with the new results within the same playlist.
Now you can add / subtract / intersect any of the existing smart playlists. You can have a smart playlist just to mix different lists into one (just fusion rules, no other rules), or you can mix the results of some rules with the results of other lists.

By simply tapping on "A", "B", "C", "D", "E" or "F" you cycle through the set operations "+" (union), "-" (minus) or "=" (intersection).
Adding is done first, then all subtractions are done, finally all intersections are executed.
In the above example for smart playlist "E", all songs with BPM < 160 are selected in the iPod music library, then these results are joined with the current results in list "B" and "D" and then this result set is intersected with list "A".

New feature in v4.6: Intersect new search results with existing list

You now will have 4 options to build a smart playlist:

1. Replace the previous results with the new results
2. Add the new results to the existing list
3. Subtract the new results from the existing list
4. Intersect the new results with the existing list (to get only the songs common to both result sets)