- Implement for POSIX and Win32, TODO for OS X
- Use this instead of ad hoc code in wxDateTime::ParseFormat()
- Remove HAVE_STRPTIME, we don't need nor use strptime() any more
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@59914 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775