Log Message:
Update to 1.23

Upstream changes:
1.23      2018-12-31 14:28:16 -0500
  - Internally use IS_WIN instead of IS_DOS for DOS/Windows style
    operating systems.  This is 2018 (almost 2019) after all.
    IS_DOS is now an alias for IS_WIN, although these are not public
    interfaces so you shouldn't be using them anyway.