latestOr -> pool

Seems more symmetric this way...
Update README.md

Examples, summary, etc.
Motivation

I think this is a better pitch for why `coast` matters.

A few minor fixes thrown in as well.
Remove broken example

This job requires a cycle in the graph, which is not supported yet.
Update README.md
Round out the 'concepts' documentation sketch
Document the flow-builder

Needs a bunch of work, but what doesn't?
More and better Samza notes
Quick, useless changes to concepts doc
Update README.md

Flesh out example in README
Update README.md

More future work, better description.
Add Apache License and notice

It's an Apache universe, so might as well tag along.
Fix errant space
Add some WireFormats and helpers
Add an integration test

Whew! That got a bit ugly.

I can't warrant against memory leaks / etc, but this seems to complete
reliably.

Next up is to track the checkpoint log, so I can lose the hilariously
long sleep...
Configure checkpoints and changelog
More normal naming for package object
Rename test and make more general

Now it inspects config to see all the topics it should tail.

This is pretty good now; I should be able to add more tests without
messing with it too much.
WIP: exactly-once stream offset tracking

Only pure transformations work right now, but it's a start!

This relies on a patch to Samza that allows the flush of a single input
stream. This is necessary to ensure the downstream output will be
persisted before we save the offset pair.
WIP: exactly-once aggregations

Plus the usual thrashing.