Merge the listen-protocol sandbox branch to trunk.

I will be adding documentation for the new directives hopefully in the next day or so.

* server/core.c: Added 'Protocol' to the core module config
                 Added ap_{set,get}_server_protocol API.
                 Added new directive: 'AcceptFilter'.
                 Enable 'httpready' by default on systems that support it.  Use dataready filters for others.

* server/listen.c: Attempt to inherit protocols from Listener Records to Server configs.
                   The 'Listen' directive can now optionally take a protocol arg
                   Move bits that determined which accept filter is applied to core.c.
                   Added bits to find the correct accept filter based on the core's configuration.

* include/{ap_listen.h,http_core.h}: Add Protocol to respective structures.

* include/http_core.h: Add the accf_map table to the core_server_config structure

* include/ap_mmn.h: Minor MMN Bump for the new interfacces.

* modules/ssl/ssl_eng...