Trevor Merrifield

Encode/decode using native endian instead of little endian. While we're at it, get rid of the `byteorder` dep now that https://doc.rust-lang.org/stable/std/primitive.i64.html#method.to_ne_bytes is available.

A Node.find_focused function would be nice. I wrote out an example in https://github.com/tmerr/i3ipc-rs/issues/29 but we have to remember to check floating_nodes too. An iterator across the entire tree might be...