Ensure that in "Shuffle All" mode the "Next" button on the springboard always has an item available

[maihde]

Currently, the Shuffle All works by grabbing a list of random songs. When it reaches the end of the list is grabs another set. However, when on the very last song the "Next" button doesn't list a song title because the list had not yet been grabbed.

The following changes should be made:

• Fetch the next set of songs when only one song is remaining in the list
• On the "Show Queue" screen provide a psuedo-song at the end of the list called "Fetch More".