Revision 1469982

2nd attempt to fix issue #4355 'svn_client_log5 broken with multiple
revisions which span a rename'.

Note from the future: All non-test portions of this change were
reverted in r1470566.

* subversion/include/private/svn_client_private.h

  (svn_client__resolve_rev_and_url): "New", was previously
   libsvn_client/ra.c:resolve_rev_and_url().

* subversion/libsvn_client/log.c

  (svn_client_log5): Once again, reparent RA session if necessary, but this
   time handle discrete revisions in *any* order, handle WC targets properly,
   and deal with pre-1.5 servers.

* subversion/libsvn_client/ra.c

  (resolve_rev_and_url): Convert from static to svn_client private function,
   renaming from this to...

  (svn_client__resolve_rev_and_url): ...this.

  (svn_client__ra_session_from_path2,
   svn_client__youngest_common_ancestor): Update calls to defunct
   resolve_rev_and_url().

* subversion/tests/cmdline/log_tests.py

  (log_multiple_revs_spanning_rename): Remove XFail decorator.  Tweak
   comments re failure status.