bug 4321: ssl_bump terminate does not terminate at step1

bug 4321: ssl_bump terminate does not terminate at step1

The following trivial configuration should terminate all connections that
are subject to SslBumping:
  ssl_bump terminate all
but Squid either splices or bumps instead.

This patch fixes Squid to immediately close the connection.

Also this patch:
 - solves wrong use of Ssl::bumpNone in cases where the Ssl::bumpEnd
   (do not bump) or Ssl::bumpSplice (splice after peek/stare at step1)
   must be used.
 - updates %ssl::bump_mode documetation.
 - fixes %ssl::bump_mode formating code to print last bumping action

This is a Measurement Factory project