loop4r_read for controlling sooperlooper via an FCB1010 with the EurekaProm
set to I/O mode. The goal is to allow control of sooperlooper via just the
controller and have the LEDs etc reflect the state of sooperlooper.

Forked from the https://github.com/gbevin/ReceiveMIDI and
https://github.com/gbevin/SendMIDI source as a MIDI starting point.

To use it, start sooperlooper with the included session and midi configuration files
that contain four stereo loops and midi bindings. Start loop4r_read and loop4r_leds
and then use QJackCtl to set up your audio in/out and have the virtual midi
device loop4r_control_out output into sooperlooper.