Further to r599711; document new API guarantee for handling non-NULL

request_rec pointer when adding connection filters; minor MMN bump:

* server/util_filter.c (add_any_filter_handle): Set f->r for
  connection filters even if passed-in r is non-NULL.  Style nit fix
  also.

* include/util_filter.h (ap_add_output_filter,
  ap_add_output_filter_handle): Document new API guarantee.

* include/ap_mmn.h: Minor MMN bump.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@600473 13f79535-47bb-0310-9956-ffa450edef68