Reported-by: Theo Belaire <tbelaire@uwaterloo.ca>

Add a --no-echo flag to the insert operation so that the password isn't
echoed when entering it. This requires the user to echo the password
twice for confirmation.

Reported-by: Dominic Lüchinger <d.luechinger@snowgarden.ch>

This also prevents showing the second <word> of the password in the
prompt.