Commit 60 (Beta Candidate)

- Some bug fixes for childTags() API when in element-only
  content.

- Additional work on data-linking with deep paths and
  using "onerror" - plus memory leak bug fix, for scenarios
  called out in:
  https://github.com/BorisMoore/jsviews/issues/281

- Some additional bug fixes.

- Many new unit tests added.