Update README.md
Some initial architectural thoughs, based on a bunch of conversations
Merge pull request #1 from ReturnPath/rm/thoughts-from-today

Write down my understanding of the system we described today.
Make README reflect additional thoughts in other documents
Prototype of the handling portion - scheduling is a no-op

Mostly intended to give us something to talk about.
Add some super basic comments
Fixing some bugs
Prettify logging, add 'cron' execution type, clean up some stuff
Docs, and base64 decoder method for KV model