* switch 3.12 back to tiny-ec2-bootstrap (tiny-cloud requires ifupdown-ng)
* restrict cloud-init to 3.15+
* pad UEFI firmware so QEMU works with aarch64 again
* kinda fix motd release_notes (more to do yet)
* switch to tiny-cloud instead of tiny-ec2-bootstrap
* set default NTP server, if configured
* add default /etc/network/interfaces
* add urlopen() timeout to mitigate ipv6 issues connecting to alpinelinux.org