Correctly nest comments.

Fixes bug #46636.

This was caused by 817a74bc3792f409c9b66eac9a894ef6777c24b5, where
commentData()'s middle parameter ($review) was removed, but the call to
commentData() in saveComment() was not updated accordingly.

Based on my very limited tests, $review seems to be 0 always, whereas
$parent is the parent comment's ID when we're replying to a comment.
Because the parameter order was changed when one parameter was removed,
$review unintentionally became the new $parent, and as a result, all
comments were treated as new top-level comments, even if they were replies
to other comments.

Also bumped version number.

Change-Id: I8d6d576fa9f3c15bef2e19310efc0b2265f8a618