pwg: drop -u from the usage, there's no such option

rewrite pwg in perl; fix diceware-style generation issues After a discussion with Alexander Arkhipov turned out pwg had some major issues: - `sort -R' is non-standard (although quite popular) - `sort -R' is not required to employ good randomness - `sort -R | head -nX' has less entropy than a true diceware (not all words have the same probability) So, rewrite it in perl where it's easier to roll an arc4random-esque function on top of /dev/urandom. randline() employs the same algorithm used by arc4random_uniform(). The new diceware generator code was based on a sample code provided by Alexander Arkhipov, thanks!

pwg: guard against possible flag-injections

fmt

add pwg: password generator