Move a backwards compatibility wrapper for svnserve versions 1.0-1.1 to the
ra layer. This will slowdown 'svn list' and 'svn info' a tiny bit for some
cases when using these old versions because we can't limit the ra calls
on knowledge in the callers, but this will make the ra layer easier to use
and maintain. (Callers can stop worrying about this limitation in old
svnserve versions)

We can't really move this in ra_svn as within ra_svn we can't use the normal
ra apis.

* subversion/libsvn_client/client.h
  (svn_client__ra_stat_compatible): Remove function.

* subversion/libsvn_client/info.c
  (svn_client_info4): Use the normal ra function.

* subversion/libsvn_client/list.c
  (svn_client__ra_stat_compatible): Remove function. Move code to ra layer.

* subversion/libsvn_ra/ra_loader.c
  (includes): Add svn_time.h.
  (svn_ra_stat): Move svnserve fallback code here.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1552441 13f79535-47bb-0310-9956-ffa450edef68