affstats: invalid option -- 'v'

Hi,

When using affstats -v, the command says:

```
affstats: invalid option -- 'v'
affstats version 3.7.16

usage: affstats [options] infile(s)
      -m = print all output in megabytes
      -v = Just print the version number and exit.
```

The right option is -V (not -v). Please, fix the manpage too.

Cheers,

Eriberto

