[Android] Separate preload settings re. WiFi/Power

[bemymonkey]

I've just noticed a missing feature that would be FANTASTIC to have:

Separate options for the "Songs to preload" setting.

WiFi + AC Power
WiFi + Battery
Mobile Data + AC Power
Mobile Data + Battery

So for instance, you could set:

WiFi + AC Power: Download all songs in playlist ("Unlimited" setting)
WiFi + Battery: Download 10 songs (since WiFi is fast, the battery hit for downloading 10 songs in advance shouldn't be too high)
Mobile Data + AC Power: Download 10 songs (No problem with power usage, and I have a 5 gig mobile data allowance that's used almost exclusively for Subsonic)
Mobile Data + Battery: Download 3 songs (Mainly for power savings, as 3G downloading draws a ton of battery on my device)

It would be great to be able to customize these settings according to the criteria mentioned above.