todo

非常经典的加密算法

* Add a -s parameter to allow other than 128-bit passwords.
* Create 'man' pages (this program currently breaks my policy of
  'release no program without a man page'!). 
* Create a HOWTO document detailing how to use this *securely* in
  shell scripts and such (in particular: *NEVER* save unencrypted
  passwords on the disk! And, 'md5sum' is your friend!).