Merge branch 'develop-olympus' into develop

* develop-olympus:
  [ticket/12176] Reword comment about config entries.
  [ticket/12176] Add newest_user_colour to config array to ensure it exists
  [ticket/12176] Display correct message when trying to delete founder.
  [ticket/12176] Add functional test for founder deletion message.

Conflicts:
	tests/test_framework/phpbb_functional_test_case.php