shared data between specs
Add image visualizing idea of data being shared between specs

Add image files, caption and update the PDF as well.
Add reference to 'data' image in text
Explain what the arrows mean in the DescribeSML module image
Adjust caption widths
Add example code listing
Add matcher and spec to glossary and add paragraph about printing different types
Make first DescribeSML example more self contained and add example of using let-in-end

I'm not particularly fond of how this bloats the code...
Rant about inflexibility of static typing
Order of list elements should not matter in matchers
Compare with QuickCheck (Haskell)
Success criteria for QCheck
Compare ease of writing tests ad hoc in SML compared to Java
Add QCheck and Formal Verification subsection, and restructure notes
Package manager and distribution aspects
Mocking and stubbing in SML
Some general thoughts on TDD
Move notes into other section
Thoughts on why people don't test SML so much
Looong section about testing in education ;)