Looking to add a few extra fields / options

[justmobilize]

Hello!

This is a great library and we've been using it internally for a few things, but as we've grown are finding it a bit harder to do a few things. I was wondering if you would be open to the following things (would do a PR + tests):

1. Add a fifth Action of download. Although similar to access - it's more specific then just seeing data
2. We need to easily show related changed (via foreign keys) and had the thought of adding a parent_id field. It would be up to the user to populate this, but would be an additional index field that one could query on to get all the changes
3. We have an even odder case where we have 2 levels of parents. I would love to add owner_id (or something) to be able to globally get everything under the top level.

We can probably get by with just 1 and 2, but wanted to get all my asks together.