listsinceblock had a double ellipsis (elision + continuation); this looks ugly, just one is needed.
Elision ellipsis wasn't getting a comma, so was truncated to ".." by comma-removal code.
Elision ellipsis was indented incorrectly (as if it was a subitem).
Similarly, type "none" would get truncated to "Non", when it should really be "null" anyway.
This is a backport of Core PR18508
Related to D8892