o# This is a combination of 14 commits.

Start modularizing packet

move header into its own chunk, include tests

Move auto_respond as a class method

Move packet into its own file

rename "packet" to "message"

Rename Response and Request to *Type to free up the names

Added request and response, pretty clunky feeling though. How can I refactor this?

Better consistency using "message" for the packet inside a Request/Response

cleanup `use`s a bit

more cleaning

Cleanup before pull request

Add tests

Add response test

Cargo fmt