Avoid PHP notices in wp_notify_postauthor() when using a custom comment type.
Use a switch statement for consistency with wp_notify_moderator().

fixes #25880.

git-svn-id: https://develop.svn.wordpress.org/trunk@26114 602fd350-edb4-49c9-b593-d223f7449a82
Use case-insensitive comparison for email addresses. fixes #25779.

git-svn-id: https://develop.svn.wordpress.org/trunk@26115 602fd350-edb4-49c9-b593-d223f7449a82