A re-run message for appendix numbering
Chapters in ToC look nicer bold.
Use ignoremissingmainmatter in tests.
Rename single-driver test suites.
Enhance the abstract environment so that it works in both front matter (as a chapter) and main matter (as a section*).

Fixes #23.

Includes tests in both a full dissertation and a single chapter.
Additional overall tests on the dummy example.