Fixes #1441.
Cleaning up StopForumSpam checker
Fixing IP address handling in log_spam_block()
Fixing undefined $this->lang in class StopForumSpamChecker.
Removing usage of json_last_error() to maintain PHP 5.2 support.
Merge branch 'feature' of https://github.com/euantorano/mybb into fix-1441
Merge pull request #1442 from euantorano/fix-1441

Fixes #1441.