Include the other interface configs from /etc/network/interfaces.d/ after lo
and existing eth*, as was initially intended.
Also separate out the assembly code into its own script, as this is done both
on boot via eth-eni-setup and on hotplug events by etc-eni-hotplug.
Resolves#91
* eth-eni-setup init script
before networking starts up, makes sure eth interfaces match attached ENIs
also fixes a permissions problem with eth-eni-hotplug mdev config
* fix aarch64 build