Old password required for changing existing password

System should ask user his old password before changing current password. This is required for all users.

With existing implementation, this is in working state for Employee and Company Admin. We need to implement this for Partner and Broker user.

Security page has flag "Users are required to provide current password before changing" under Change Password section at global as well as company level. When this flag is enabled, system should ask user his old password before changing his existing password.