* default to ubuntu default keyboard layout, don't override with gb
* run rc.local.txt from /boot if exists
* don't export stage4/5 images or noobs
* export stage2 -keyternal image
* don't resize root partition on first boot
* don't enable swap by default
* Added Docker support
- replaced necessity for devicemapper (through kpartx) by using parted and
losetup with offsets
- added Dockerfile
- added dependency for parted and grep
- added hints to README.md
- common: loop through unmounts, fix shellcheck warnings
* stage2: use debconf instead of console-setup patch. Fixes#41
