Adding simple script for USB stick creation.
Fixing syntax error, adding rules for debian/rules.
Adding source format for digabi-certificates package.
Adding support for vendor+local configuration.
Adding release command for preparing new releases.

Copied from Tails (file release).
Adding GPLv3 from Tails.
Adding automatic upgrade of build system.
Upgrade system in non-interactive mode.
Removed Tails-specific code.
Restructured code.