USB output is here

Updated my Node last night to add usb output, sounds great so far. Note for Devs - it didn't automatically select my dac (Musical Fidelity mx-dac) as the output destination like it should. Initially I had no sound and had to go in and select the DAC manually via app settings, even though usb was the only output connected. Also see that there is no option to select maximum volume as a default, is that deliberate? Otherwise, good job, thanks.