Makes the output way nicer with shorter code. Also brings
systemd-analyze behaviour more in line with other systemd-programs.
Argparse is in Python since 2.6, and is available as a package for
previous versions, if someone is stuck with very old Python.
This only adds the fields to the D-Bus interfaces but doesn't fill them
in with anything useful yet. Gummiboot exposes the necessary bits of
information to use however and as soon as I get my fingers on a proper
UEFI laptop I'll hook up the remaining bits.
Since we want to stabilize the D-Bus interface soon and include it in
the stability promise we should get the last fixes in, hence this change
now.