Un-muddle graph inversion CLI code
Un-muddle graph inversion CLI code

The temporary code to handle no-arguments or package-only arguments used
the inverted graph directly. Now, it doesn't use the graph directly at
all, so we can start with a non-inverted graph, and only invert it when
needed.

It's weird for me, too.

bcobb/brew_dg,bcobb/brew_dg