#576 Consecutive file re-adding on file play, changes file order

[yorgos]

Reproduce:

1. Enable "add consecutive files" on playlist settings
2. Add files A1, A2, A3, B, C with THAT order!
3. Play file A1.

Effect:

After playing file A1 (or any non-terminal on the numbered sequence), all consecutive to that file are re-added to the end of the playlist. The resulting order is:
A1, B, C, A2, A3

Expected behavior:

File order should not be changed

Ideas on how to fix:

1) If possible re add at the same position
OR
2) If file exists in the playlist skip on adding it again

cheers,
Georgios