SIH replay and SITL

Hi everyone,

I would like to implement two improvements in the SIH.

  1. have a replay mode, to replay a simulation from a real flight log.
    EDIT: It seems that there is a replay in src/modules/replay.
    I should start by exploring this functionality.

  2. SIH in SITL
    I would like to be able to run the SIH without a hardware, this becomes then an SITL setup. I want to be able to use the step by step debug tool and I want to be able to run the SIH faster than real time.
    a. Where to start? I guess I need to cancel the calls to jMAVSim in SITL mode, because the simulation engine is part of PX4.

@dagar any tips?