AS7-6465 Network partition can cause multiple singleton masters to start
JBPAPP6-1465 Unignore and fix CustomXACML authorization module tests.
[AS7-6524] For a duplicate user do not reject the addition in non-interactive mode - instead just update the existing user.

This is to bring the behaviour in-line with the documentation and the behaviour from previous releases.
AS7-6525 test changes