Output extra bh info for spin/jet model

When I introduced changes recently to track how much mass is accreted in each accretion regime (thin, thick, slim disc), as well as how much heating/jet kicking is going on in these regimes, I neglected to modify black_holes.io to actually output this info. This branch is fixing this.

I have also added jet velocities as an output. This is useful in case we use variable jet velocities.