Support for long description

[malleor]

It would be nice to be able to add a program description to usage. I mean this kind of output:

usage: ./test --host=string [options] ... 
options:
  -h, --host    host name (string)
  -p, --port    port number (int [=80])
  -t, --type    protocol type (string [=http])
      --gzip    gzip when transfer
  -?, --help    print this message
The program accepts on standard input newline-delimited string 
values denoting query arguments to be added to the output url. 
Example: 
  $ (echo a=1& echo b=2)| ./test --host=github.com -p 4545
  http://github.com:4545?a=1&b=2

I don't know whether is makes sense for Unix people, but it does on Windows.