server: Option `-F' to run the server in the `foreground'.

server: Option `-F' to run the server in the `foreground'.

This means that the server will quit when it sees EOF on standard
input.  Useful for testing, since it means that your processes aren't
going to continue running after you let them off the leash.

Also make tripectl pass `-F' to a tripe that it's starting up so that it
won't continue without (say) logging.