Creating a new test

1 create the main code for the test in src/class.Checker.php. Additional code can be created in class.Parser.php when it is a question of scanning the page for information (so that the scanning doesn't need to be done for each check).

2 create the messages in langs/en.properties

3 create an outline in /International/quicktips/checker

4 create some tests in /International/tests/i18n-checker/data.php

5 check tests with W3C HTML validator for additional ideas

6 add tests to tests/tests_xxx.properties