[Terrapreta] Charcoal Specification Development

[code suidae]

I posted another updated model. I added and Event entity with date and
details fields and set up PyrolysisEvent, AmendmentEvent, Analysis and
TrialLogEntry as descendants. This mostly just makes it easier to
build a timeline view of what events happened when.

To the best of my knowledge, and baring minor flaws in capturing the
model in UML, this version of the document represents a comprehensive
model of a charcoal and cultivation experiment logging system.

At this point, unless someone can suggest revisions, I'm ready to
start coding a 'workhorse' app that I can use to assist in developing
and testing the data interchange portions of the system.

Dave K
-- 
"Our ignorance is not so vast as our failure to use what we know." -
M. King Hubbert