Commit 2 of 2 to:

1. rename ap_rset_content_type to ap_set_content_type
2. reverse the arguments to aligh with ap_set_content_length


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@94057 13f79535-47bb-0310-9956-ffa450edef68