Dump and restore the space globals

Fixes #574 (closed)

By saving the state of the space globals. Note I kept these as globals since some are used in contexts without access to a space struct.

@aborissov can you check this works for you? Please assign to @matthieu when you are happy.

Works for me.

assigned to @matthieu

Thanks both! Does that mean it works with and without star formation on?

We are just checking without in this case.

Ok, thanks.

Checking if it works with star formation just now

It works with star formation also.

Thanks. All good for me. I'll accept this. Should pave the road to the restarting with feedback.

merged

mentioned in commit 1e63ffa0