Random Passwords
This class can generate random passwords, which do not include ambiguous characters,
such as I, l, and 1.
The generated password will be made of 7-bit ASCII symbols.
Every four characters will include one lower case character, one upper case character,
one number, and one special symbol
(such as '%') in a random order.
The password will always start with an alpha-numeric character; it will not start
with a special symbol (we do this because
some back-end systems do not like certain special characters in the first position).
