Set temporary files in TutorialSnippets to be auto deleted.
Remove @Ignore annotations.
Add comments showing how to  create non-auto-delete temp files.
[They're still not really testing, but if they're in the test suite,
they ought to be run.]
add .gitignore entries for non-directory format  intellij project files (.iws = per-developer state, .ipr = project config)
Improved Testing of Ontology ID comparison.

Test equals method as well as hashCode.

Test versioned ID comparison.

This merges pull request #108