Refactor DbBootstrapSubsystemParser to use the new builder API instead

    - Refactor DbBootstrapSubsystemParser to use the new builder API instead
    - Add additional test cases to test verious configuration.
    - Clean up pom.xml files
Good point. I'm unsure if this come out of the box with AbstractBoottimeAddStepHandler so I replaced it with a AtomicInteger instead. 

Maybe @ctomc know if performBoottime is thread safe by default?