Arrays

Wanted to run this by you @bryteise before you start working on array conversion.
Long story short I've just converted outgoing serialization to use BuxtonArray.
I need to know your status on epoll, so I know whats safe to touch my end :)

Also, with list-keys, do you want to a list-keys by enum ? BUXTON_LIST_BY_LABEL, or something
awful like that? Remember the backend stores a key, so you have to split the key before you can do anything with it, which makes searching pretty difficult to implement in the backend, short of having a get_all kinda thing, and iterate the search in backend.c

Thoughts? (Tests not yet added here, because I need to know where we're heading :))