Revert much of previous erroneous checkin. Add ChangeLog entry.

* pinfo.h: Correctly set __SIGOFFSET.
* path.cc (hash_path_name): Avoid calling library functions for simple copying
of characters.
* shortcut.c: Use WIN32_LEAN_AND_MEAN.
* smallprint.c: Ditto.
* environ.cc (getwinenv): Minor clarity fix.
* localtime.c: No need to include windows.h
* string.h: New file.

winsup/cygwin/shortcut.c

@@ -10,9 +10,8 @@ This software is a copyrighted work licensed under the terms of the
 Cygwin license.  Please consult the file "CYGWIN_LICENSE" for
 details. */
 
-#define WIN32_LEAN_AND_MEAN
-#include <shlobj.h>
 #include "winsup.h"
+#include <shlobj.h>
 #include <ctype.h>
 #include <sys/types.h>
 #include <sys/mount.h>