Optimize a few truename checks on Windows to use a far more efficient code
path.

* subversion/include/svn_io.h
  (svn_io_stat_dirent2): New function, allowing optional truename check.
  (svn_io_stat_dirent): Deprecate function.

* subversion/libsvn_subr/deprecated.c
  (svn_io_stat_dirent): New function.

* subversion/libsvn_subr/io.c
  (svn_io_stat_dirent): Rename to ...
  (svn_io_stat_dirent2): ... this and use the existing stat call to perform
    a truename check.

* subversion/libsvn_subr/sysinfo.c
  (includes): Add path handling.
  (win32_shared_libs): Just use our own apis instead of the apr ones, that
    perform a lot of unnecessary IO for the TRUENAME question that we don't
    even need.

* subversion/libsvn_wc/status.c
  (stat_wc_dirent_case_sensitive): Use svn_io_stat_dirent2 for a cheaper
    truename check.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1435527 13f79535-47bb-0310-9956-ffa450edef68