We can't initialize Sentry during module initialization because our
`initialize_sentry` logs some status info. Setting the logging level
later on is then a no-op, breaking verbose and very-verbose logging.
This change fixes this by putting Sentry initialization into a
separate method that gets called after we set the log level.
Also refactor some common code into methods that appear in all our
executables.
and km-package-list-installed
install the km-package.bash completion script
in the Debian package to /etc/bash_completion.d
km-package-get: doc change of download location
