The previous implementation used 'all' as the default for scope, this
could lead to surprising behaviour where a user would fetch all
references for cloned and seeded repositories. Instead have a progressive,
safe by default value - where it fetches only 'followed' references. Later
a user can decide to set the scope to 'all'. NOTE: the default policy
scope was not changed from 'all' and is intended to be changed at a
later date.
The `help` module is no longer needed, since `clap` handles that.
This meant that the re-exports of each command's `ABOUT` could be removed and
the `const`s can now be private.
Adrian Duke
Fintan Halpenny
Erik Kundt
Lorenz Leutgeb