Feature/suffle improvements

[gersonup]

1. Update LocalPlaylistStore.createShuffleQueue to first insert the current playing song as the first song, then update the randomizeSql query to exclude that song.

2. Update PlayQueue.shuffleToggle to not call playSong(position:) because that stops the music and manually set currentIndex to 0.
3. Instead tell StreamManager to removeAllStreams(except: Song) passing in the current playing song then call fillStreamQueue.

5. Then also need to modify shuffleToggle so that when you switch back from shuffle to regular play queue, it should also not stop playing the music. It should be similar to the above but set currentIndex to the index of the current playing song in the play queue playlist.

6. Fix the PlayerViewController shuffle loader hiding the HUD in the right threath.