Summary of changes:
* Extract function for creating password generator from options into
`Generate` command. This function is now reused in `Add` and `Edit`
commands.
* Updated manpage with missing password generation options.
* Updated manpage with missing longer forms of password generation options.
* Added unit tests for new password generation options in `Add` and
`Edit`.
* Handle case when `-g` and `-p` options are used at the same time.
This PR adds password generation functionalities while reducing
code duplication, but at the cost of 2 small breaking changes:
* The password generation option for `Add` and `Edit` for specifying
password length is now `-L` instead of `-l`, to not clash with the
`-l --lower` option.
* The `-u` shorthand for the `--upper` option has to be removed, to not
clash with the `-u --username` option.
* Add -U variant for uppercase.
eb1882453f