Debian lacks a package for the Raspberry Pi hciuart.service service, and
recent versions of the Raspbian package drag in raspberrypi-bootoader (which we
need to avoid because it contains a kernel), so this variant of an early
version of the Raspbian package was devised for use on TLXOS.

Our primitive version of the pi-bluetooth package assumes that Bluetooth is on
/dev/ttyAMA and not /dev/ttyS0 - Raspbian provides a /dev/serial1 symlink to
whichever of the two is appropriate via a udev fudge, but Debian doesn't have
that.

The 0.1.0tlx version uses hciattach from Raspbian's "special" build of Bluez,
whereas 0.1.0tlx2 uses btattach from standard Bluez (but requires a much later
Linux kernel).