[Etoys] Key generation

[Yoshiki Ohshima]

  Alan,

> How about just putting up an advisory message that says something like:
> 
> "This is a one-time pause to generate a special key to ensure 
> security in Squeak Etoys"
> 
> I.e. just tell the end-user what you are doing. This will be 
> sufficient for this build. (And the division by 5 sounds good.)

  Yeah, if #informDuring: would take multiple line string, it would be
easy^^;

  I'll probably put the message in a way that looks ok with the
original progressing percent message.  (I'd keep a way to inform
something is really going on.)

-- Yoshiki