Expose missing options in the repository dumpfile loader API.

Rev svn_repos_get_fs_build_parser4() to svn_repos_get_fs_build_parser5(),
adding the three flags that have been added to its implementation and used by
its 'convenience' wrappers svn_repos_load_fs4() and svn_repos_load_fs5() but
that were not exposed here. Now all the features that the wrapper provides
are also exposed by the slightly lower level API.

* subversion/include/svn_repos.h
  (svn_repos_load_fs4): Correct the '@since' version.
  (svn_repos_get_fs_build_parser5): New.
  (svn_repos_get_fs_build_parser4): Deprecate.

* subversion/libsvn_repos/deprecated.c
  (svn_repos_get_fs_build_parser4): Implement as a wrapper.

* subversion/libsvn_repos/load-fs-vtable.c
  (svn_repos_get_fs_build_parser5): Rename from ...4() and add the new
    parameters.
  (svn_repos_load_fs5): Simplify by using svn_repos_get_fs_build_parser5().


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1647563 13f79535-47bb-0310-9956-ffa450edef68