[FEATURE] For non-readable Deezer tracks referenced by a playlist, get an alternative version

[slanglade]

Is the feature request related to a problem. Please describe it.

Sometimes, tracks gets a new Id in Deezer. But if you have a playlist that is referencing the old Id, it won't be downloadable anymore.
The Deezer application (web, Android etc.) is smart enough to get the new Id and you won't even notice that something has changed.

Describe the solution you would like.

If I have a track in a playlist that is not readable anymore, try to use the "Alternative" field of the track itself.
If there is no track in the "Alternative" field, then initiate a search on artist + album title + track title, to get the new id.

Describe alternatives you've considered.

Update the playlist in Deezer, but it is really not easy to do, as there is absolutly no usable way of identifying such track referenced with obsolete IDs.

[slanglade]

I've worked on a fork of the repo, it's looking good so far. @nathom, may I submit a pull request for this one (and the better file and folder naming management) ?

[nathom]

Sure, submit and I will review it.