Extracted commit messages guidelines into separate linkable section. Require capital letter in the summary. Added guidelines on linke the original pull request.
Change ticket reference style from Javadoc @see DATA…-??? to @Test // DATA…-???. Using @see requires either a Java symbol or a valid HTML link <a href=…>…</a>. To not include links to resources that might change, we decided to put the ticket reference directly after the test annotation.