Slightly clarify the control spec

           'tor --hash-password <password>'

  or by using the example code in the Python and Java controller libraries.

  To authenticate under this scheme, the controller sends Tor the original

  secret that was used to generate the password.

  secret that was used to generate the password, either as a quoted string

  or encoded in hexadecimal.

5.2. Don't let the buffer get too big.