README revamp

The way I typically want to evaluate simple-ish libraries:

 1. Terse intro.
 2. Show me how sexy some code looks.
 3. Okay looks pretty sweet, how do I get it running?
 4. I'm intrigued enough to want to see more of what it can do now.
 5. *Maybe* I want to know more about implementation details.
 6. I'm going to hack on this, how do I run tests?

My totally subjective sensibilities, but I just want less verbiage
before an example and installation procedure.
Remove extraneous docstrings
Track SBT version for reproducible build setup
Use the built-in sbt integration test setup

http://www.scala-sbt.org/release/docs/Detailed-Topics/Testing#integration-tests

Might want to get Betamax going someday.