afc: Use g_message() and g_debug() instead of g_print() for log output
Daemons shouldn't be printing directly to stdout, but should be using
the normal GLib logging system. The messages output by this daemon
can now optionally be prefixed by process name when
G_MESSAGE_PREFIXED=all
is set in the environment, which allows them
to be identified and filtered more easily in log output from the D-Bus
daemon.