Prevent AP_FILTER_ERROR from being misinterpreted as SUSPENDED when checking

the status code returned by a handler by updating the values of the filter
error macros and consolidating them in httpd.h 



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@721677 13f79535-47bb-0310-9956-ffa450edef68