"Auto" playlists

[kevinfrei]

Allow playlist descriptions involving artists, albums, years, keywords, etc...

[kevinfrei]

Basically, allow playlists to be 'textual' descriptions in JSON (trivial to parse...):
Start with 'none' or 'all' and go from there. default "op" is "add" not "remove". An array is 'or' and an object is 'and', sort of...

{ "none/all": [
    {"artist=": "smashing pumpkins", "album~": "collie"},
    {"artist~": "foo fight", "title~": "everlong", "year<": 2000},
    {"op": "remove", "playlist": "bad-words"}
  ]
}