This is mostly just some cleanup of the various implementation types,
but it also adds a 'marker' interface for decrees, IDecree

Cleanup pass to uniformize things

utils.esodata now also lives in the esodata project; not here

Tests are now in a 'test' sub-package, so it is clear that they are
indeed test code, not just disjoint parts of the main code

Cleanup files, and add missing comments in places.

This adds both an ability to get the column at which the indent ended,
as well as some basic page control.

ReportWriter now has support for different indent types at various
levels. This is useful for Word-style bulleted lists