liquibase.integration.commandline.Main is not extensible

If I want to implement my own cmd line tool using Main, it’s currently impossible because of getClass().getDeclaredField() call - getDeclaredField doesn’t return inherited fields. This should either replaced by an iteration all over the hierarchy or by a simple liquibase.integration.commandline.Main.class.getDeclaredField

I think it would be best to allow getDeclaredField to check the entire hierarchy, not just liquibase.integration.commandline.Main.  That way the properties file support would allow you to set custom parameters.

If you could make the necessary changes to Main and send them as a patch (or commit them and I can review them), that would be great.