hub/adc: Init NORMAL state on own INF + allow MSG outside NORMAL

The ADC spec (1.0.2) is confusing with respect to when the NORMAL state
starts, and not consistent with what other hubs and clients actually
implement. This current solution is approximately what DC++ and ncdc do,
and should fix the login sequence on some hubs. (At least Flexhub,
ADCH++ and LUADCH)

I also removed the listcomplete flag, since it's now equivalent to
the transition to the NORMAL state.