Run context should also be on tape?

[sirmarcel]

title says it all.

Upsides:

• Once you ran prepare(), restore and run will always do (approximately) the same
• If you encounter a tape.son in the wild, the information in it is slightly more complete

Downsides:

• Need additional functionality to overwrite the context in restore if required
• More complex restore

Also, it might be worth thinking about including more general (write-only) metadata on the tape.