Multiartist: Replace separating characters with ";" in places of separation

[Xaphan]

This is more of a disadvantage than a bug. Due to the lack of this function, the library lacks unification. For example, if the library contains files of different standards (id3 + vorbis), the captions will look like this: artist / / artist2 and artist; artist2. This in my opinion conspicuous

[andrewilley]

In any diverse collection of songs I think it's pretty much a forgone conclusion that there will be many different separators between artists. I've gone through and edited many of my own files to update instances such as "and" or "&" and change them to semicolons so they can be parsed neatly.

It's a bit of a manual checking process though, as while I obviously needed to change terms like "Queen & David Bowie" to "Queen ; David Bowie", I also needed to leave proper group names such as "Adam and the Ants", "Siouxsie and the Banshees" and "Earth, Wind & Fire" alone. I also didn't alter some of the more-established conventions, such as "Robin Thicke feat. Pharrell" and "Gotye feat. Kimbra" and I added "feat." to my separator symbols list in PA. For what it's worth, my eventual Separator Symbols list settled down to:   feat.  ft.  w/  ;  //  /  \\

It's that variety of terms which works best with Max's approach of showing the original unparsed strings verbatim on subtitle lines. It means I can still see what the song artists intended - such as "Robin Thicke feat. Pharrell" - if that's what the tag says.

Vorbis supports multiple instances of the same tag name (such as several tags named "ARTIST" or "ALBUMARTIST") so it has no need of any physical separator strings like ";" or "//" at all. ID3v2.4 also allows for null character separators within its TPE1 and TPE2 tags, which does the same job but is far less common in the wild. I did suggest that it might be nice to indicate in PA when that occurs, such as by using blob characters in lists. So a file of "Dancing in the Street" which contained two individual ARTIST tags would be shown as being by "David Bowie ● Mick Jagger" rather than "David Bowie ; Mick Jagger" (as the latter could also have been a single string).

Andre