Change password algorithm to be more secure.

On my system, /usr/share/dict/words contains 99,171 words. According
to xkcd[0] that means about 16 bits of entropy, or 80 bits for a
5-word password. Throw in two digits and a punctuation character just
to appease some website's password requirements, and that's 11 extra
bits, and you get a password that has 99 bits of entropy.

Oh, and all this in 10 lines of code, too ;-)

[0] http://www.explainxkcd.com/wiki/index.php/936:_Password_Strength