When operating FreeBSD, the argument crypt_id is passed to an
overridden method chpasswd() in the FreeBSDDistro class. The definition
of this method does not contain an argument for 'crypt_id' or
'salt_len'. To address this issue, add **kwargs to the definition of
chpasswd() in the FreeBSDDistro class.

…din()

The method ext_utils.run_send_stdin() (in extensionutils.py) requires
the second argument, cmd_input, to be a bytes object, not a string
object. This is due to the usage of: subprocess.Popen().communicate().
Encode the password as utf-8 when passing to ext_utils.run_send_stdin().

/etc/user.defs is the shadow configuration file. FreeBSD user management
uses the pw utility.