First cut at input task example for chapter 7.

While this works, it needs some rejiggering for

(a) readability
(b) usability
(c) motivation

But at least, it outlines the simplicity of adding developer friendly hooks.
Fix formatting of columns when running queries.
Clean up some derby code so the example only needs one input task.
Adding databse migration testing code for chapter 7.
Cleanup examples.
Fixes to examples from writing.
Merge branch 'wip/chapter7'