Ev2 shims: Several improvements to the svnrdump code path, including accessingthe correct base revision and implementing kind fetching.Current number of Ev2 test failures: 16* subversion/svnrdump/dump_editor.c (dump_edit_baton): Track the revision we're currently dumping. (fetch_base_func): Use the proper base revision, if none is given. (fetch_props_func): Fixup path, and use the proper base revision. (fetch_kind_func): New. (svn_rdump__get_dump_editor): Track the kind fetching function, as well as the current revision.* subversion/svnrdump/svnrdump.c (replay_revstart, replay_revisions): Provide the current revision when getting an editor. (dump_cmd): Parent the extra ra session at the repos root.* subversion/svnrdump/svnrdump.h (svn_rdump__get_dump_editor): Add revision param.