aws-host-fingerprints output check

Throw a warning (with code 2) if output does not contain host
fingerprints.
smooth v0.8

Makefile:
  added userlist to ADMIN_SCRIPTS

doc/s for smooth source control.md:
  added 'remove-force', 'commit-quick-local', 'here', 'forget'.
  added (git only) 'stage', 'stage-patch', 'commit-all', 'commit-all-quick', 'diff-staged'.
  added (git specific) 'status-short', 'jump'

  added explanations

  fixed misplaced backtick for 'forget-patch'

  removed 'commit-local' for svn

smooth:
  Added stuff to comment header, e.g. Licence, Version, Keywords

  added git_current_branch(), git_which_branch(), git_remote(), git_url()

  git_transfer() now uses git_which_branch() and git_remote()

  git_commit() accepts -l and -q

  git_commit(), git_commit_paranoid():
    refactored core functionality into git_do_commit()

  added git_do_commit() (uses $git_use_staged and argument testing)

  -d option; enough of them uses dispatch_debug()

  Major refactoring of toplevel recognition code.
    no longer uses fn() -- core work moved to dispatch()
    dir_only(), set_toplevel(), maybe_clear_args(), maybe_start_arggroup()
    split detection of .svn and others

  new alternatives for example commands

  git and hg specific overrides for 'commit', 'commit-quick',
  'commit-local', 'commit-quick-local'

  added 'stage' (git only)

  removed 'track'

  renamed $arg to $action and "operation" to "action"

  added Command-line parsing section

  labelled Preparation and Processing sections