Divide torrc.sample into torrc.sample and torrc.minimal

torrc.minimal is now the one that should change as infrequently as
possible.  To schedule an change to go into it eventually, make your
change to torrc.minimal.in-sample.

torrc.sample is now the volatile one: we can change it to our hearts'
content.

Closes ticket #11144
Fix: typo in torrc.sample.in
Use 'Bytes', not 'B', in torrc.sample.

Also put this change into torrc.minimal.in-staging

Closes ticket 10343
Merge remote-tracking branch 'public/torrc_minimal'