Merge lp://staging/~echaskes/unity-control-center/fix-user-password-dialog into lp://staging/unity-control-center

Updated um-password-dialog.c to removed users to change password mode to regular when locking the account

There is currently a bug in the User Accounts password dialog box: if a user has been set to "Log in without a password" and is subsequently set to "Disable this account", the user is not removed from the nopasswordlogin group. The result is that the user can still log in without a password, even though an admin has locked the account. This is a security issue.

This is easily tested by following the above steps and confirming the users group memberships.

The bug stems from lack of a single line of code in um-password-dialog.c

Current code (starting line 268) locks user, removes automatic login, but does not change password mode:

                case UM_PASSWORD_DIALOG_MODE_LOCK_ACCOUNT:
                        act_user_set_locked (um->user, TRUE);
                        act_user_set_automatic_login (um->user, FALSE);
                        break;

Proposed code also changes the password mode:

                case UM_PASSWORD_DIALOG_MODE_LOCK_ACCOUNT:
                        act_user_set_locked (um->user, TRUE);
                        act_user_set_automatic_login (um->user, FALSE);

                        /*Set the password mode to regular in case the user is currently in the nopasswdlogin group.
                        Otherwise, the user will still be able to login even though the account is disabled. */
                        act_user_set_password_mode (um->user, ACT_USER_PASSWORD_MODE_REGULAR);
                        break;

This is easy to test by compiling/installing the code, then perform the above steps again. The user will be properly removed from the nopasswordlogin group.