Update Password

Update the web login password for a given client.

• The new password must adhere to the rules governing password
  validity and history to be accepted.
• These rules can be retrieved at the GET/System/Passwords
  endpoint.
  
• Optionally, the client's old password may also be sent. If this is done,
  the supplied old password must match the client's current password.
  
  This option is provided to avoid having a separate password
  validation endpoint when implementing consumer-facing applications.