Add ability to highlight dead entries in playlist

[Rigel88]

Some ability to have missing files indicated in the playlist would be nice. Winamp had this.

[regorxxx]

Agree, on the playlist viewer this would be a great thing.

Instead of adding it as a base behavior, it could be added as an additional style script function. i.e. something like $fileExist() which would return true/false. That would allow to paint rows or columns in red, for ex., for dead items. While also allowing some kind of customization for streams, colors, etc.

People who don't care about it would not get any impact performance.