add more factories.
more tests.
reporters tests. some meta-programming.
test boundary calculation.
getAttribute, hasChildren, assigned, url.
Merge remote-tracking branch 'origin/dev' into feature/more_timelines_unit_tests
changelog.
New version; updated changelog
Distributes WP attributes over two tables
Makes helper methods private
Introduces empty tag for (non-)impaired users
Renames variable
Adds changelog entry
Renders empty element tag from view
Uses refactored empty element tag implementation
Distributes work package attributes evenly
Handles empty hook results
Merge remote-tracking branch 'opf/dev' into feature/more_timelines_unit_tests

Conflicts:
	doc/CHANGELOG.md
Concatenate arrays and discard flattening
Shorten memoization in accessibility helper