Archaius 2.x feedback

[costimuraru]

I've been poking around with archaius 2.x and a few things came to mind. I'm trying to understand where I can contribute so that it aligns with your long terms views for the project.

But first of, great job! I'm really liking the new structure in archaius2. We're insane about performance (especially in one of our apps) and was a bit disappointed in the performance impact of governator1+archaius1 combo. I actually performed a few tests and archaius2 seems to bring a 5x perf boost in the regard. So, kudos! I'm still trying to get my head around the new config structure though.

Suppose I have this config:

test.first_key : value1
test.second_key : value2
test.nested.third_key : value3

And this config class:

@Configuration(prefix = "test", allowFields = true)
public class ServiceConfig {
    public String first_key; // This works
    public String second_key; // This works

    public String nested_third_key; // This is not working.
}

Here are some questions:

1. How would one initialize the test.nested.third_key inside the ServiceConfig? Is this not supported? What would be some alternatives if not.
2. Having to use underscores inside the variable names (String first_key) does not follow Java guidelines. Is it possible to use camelCase (String firstKey) and still have the value assigned the right config (first_key)? It some situations ( mine :-) ) it's not that easy to just change the config key to camelCase instead.
3. From what I've seen it's not possible to directly inject a field configuration, like in archaius1. Is this the final call or are there future plans to support this?
   @Configuration("config.path") String key
4. Injecting a List<String> config is not yet supported?