mod_lua: Prevent HTTP Response Splitting by not allowing tables in the request_rec to be set with values containing newlines. This is a semi-ugly hack, but it will have to do until we find another way of setting these values.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1582262 13f79535-47bb-0310-9956-ffa450edef68