Feature: #EXTBLOG-75 - Moderation only of the first comment

See https://jira.typo3.com/browse/EXTBLOG-75


A new value for the moderation settings allows to auto approve comments if a comment with the same email address has been approved before.

plugin.tx_blog.settings.comments.moderation = 2

If the setting plugin.tx_blog.settings.comments.moderation is set to the value 2 a new comment with an author email address which has been used in an other approved comment will automatically set to status approved too.