shift some processing of "core" WebDAV properties out of the generic

shift some processing of "core" WebDAV properties out of the generic
property handling code, and into a new, core liveprop handler.

*) add std_liveprop.c to deal with the core DAV properties
*) move DAV:resourcetype, DAV:supported-method-set,
   DAV:supported-live-property-set, and DAV:supported-report-set over to the
   new handler
*) props.c::dav_get_allprops() should not look in the deadprop database for
   the DAV:resourcetype -- it is readonly, so should never be in there.
*) strip vsn_hooks from the propdb; only the core liveprops need it now
*) mod_dav.c: register the core liveprop hooks and URIs
*) fs/repos.c: stripped DAV:displayname and DAV:source, in favor of letting
   the core handler deal with them.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@87075 13f79535-47bb-0310-9956-ffa450edef68