crypt - encrypt a string

string crypt( string str, string seed );

Crypt the string 'str' using the first two characters from 'seed' as
a seed. If 'seed' is 0, then random seed is used.

The result has the first two characters as the seed.

 Tim Hollebeek  Beek@ZorkMUD, Lima Bean, IdeaExchange, and elsewhere
