Add support for excluding fields from all concatenated fields

[tomas321]

I found it more difficult to include multiple fields from large data set, rather than excluding one or more fields from all concatenated fields. It is tested and working feature in my production ELK stack.

[ypid-geberit]

Could you check if #44 works for you? The only thing that is missing is excluding nested keys which you have implemented. #44 is based on #41 which also fixes non-deterministic fingerprint for nested hashes by sorting. You introduced JSON serialization in this PR. In general I favor your solution of using an existing serialization format than inventing a new one. If this PR is preferred by the maintainers, I would like to check before this is merged/released if JSON in ruby supports deep sorting.

Also note that this PR seems to break backwards compatibility, see #41 for details.

[tomas321]

@ypid-geberit thank you for your response and sorry for the long wait. I have looked at both of your PRs and it seems to me that your serialization method in #44 excludes by top-level key only. I'm currently incorporating the JSON deep sort utilizing the deepsort gem. As you pointed out in #41 I will include the deep_sort parameter to default to false in order to maintain the backward compatibility.

[ypid-geberit]

I'm currently incorporating the JSON deep sort utilizing the deepsort gem. As you pointed out in #41 I will include the deep_sort parameter to default to false in order to maintain the backward compatibility.

Sounds good. In this case, I would prefer your work to be merged instead of mine. Your patch will be a bigger change compared to how it was done in the past but I think it is for the better (using gems like json and deepsort).