Shanling Q2 port v2.5

• Wired headphones now win over Bluetooth. With Bluetooth on in Q2 Pod but no headset in use, Rockbox could start on a stale Bluetooth output and play silently while headphones were plugged in; it now uses the DAC whenever the 3.5 mm or 4.4 mm jack is in use.
• Plugging headphones in while playing over Bluetooth switches playback to them.

Install by unzipping rockbox.zip over .rockbox on the card; your config.cfg is kept.