Simplify add_ssi_vars() and move the ssi/cgi vars into their respective
  functions [so we may address r->subprocess_env in the ap_cgi_build_command
  win32 handler.]


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@95853 13f79535-47bb-0310-9956-ffa450edef68