karma: misc updates

* don't tarpit queue hook (might have a poor interaction with smtp_client)
* don't trap rejections from spamassassin (which is very configurable)
* add missing 'plugin' in a loginfo()
* fix a couple broken karma.ini rules
* punctuation changes
* karma.ini: add connect.fcrdns.generic_rdns = -1
Sure, I'll change it.