v0.4.2

Changed

• The command line ends through duho.run: Ctrl-C ends with status 130 and a closed
  standard output with status 1, both without a traceback. --help, --version and a
  usage error still raise SystemExit; every other status is as before.
• The cli extra needs duho>=0.7.8,<0.8 (was >=0.7.3).

Full Changelog: v0.4.1...v0.4.2