Build fixes.
code review feeback, close open comment
Ensured various XPG7 stuff are declared properly in sys/stat.h (and cleanup)
New documentation for wcslen, wcsnlen, wcscasecmp (and friends), wcsdup.
Various other tweaks and markup improvements.

@@ -19,10 +19,11 @@
  * CDDL HEADER END
  */
 
 /*
  * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright 2014 Garrett D'Amore <garrett@damore.org>
  */
 
 /*      Copyright (c) 1990, 1991 UNIX System Laboratories, Inc. */
 /*      Copyright (c) 1984, 1986, 1987, 1988, 1989, 1990 AT&T   */
 /*      All Rights Reserved     */

@@ -468,22 +469,17 @@
 #define _R3_STAT_VER    1       /* SVR3.0 stat */
 #define _STAT_VER       2       /* current version of stat */
 
 #endif  /* __i386 || (__i386_COMPAT && _KERNEL) */
 
-#if defined(__EXTENSIONS__) || \
-        (!defined(_STRICT_STDC) && !defined(__XOPEN_OR_POSIX))
-        /* || defined(_XPG7) */
-/* for use with futimens() and utimensat() */
+#if defined(_XPG7) || !defined(_STRICT_SYMBOLS)
 #define UTIME_NOW       -1L
 #define UTIME_OMIT      -2L
-#endif  /* defined(__EXTENSIONS__) ... */
+#endif
 
 #if !defined(_KERNEL) || defined(_BOOT)
 
-#if defined(__STDC__)
-
 #if !defined(__XOPEN_OR_POSIX) || (_POSIX_C_SOURCE > 2) || \
         defined(_XPG4_2) || defined(__EXTENSIONS__)
 extern int fchmod(int, mode_t);
 #endif /* !defined(__XOPEN_OR_POSIX) || (_POSIX_C_SOURCE > 2)... */
 

@@ -502,58 +498,22 @@
         defined(_ATFILE_SOURCE)
 extern int fstatat64(int, const char *, struct stat64 *, int);
 #endif /* defined (_ATFILE_SOURCE) */
 #endif
 
-#if defined(__EXTENSIONS__) || defined(_ATFILE_SOURCE) || \
-        (!defined(_STRICT_STDC) && !defined(__XOPEN_OR_POSIX))
-        /* || defined(_XPG7) */
+#if defined(_XPG7) || defined(_ATFILE_SOURCE) || !defined(_STRICT_SYMBOLS)
 extern int mkdirat(int, const char *, mode_t);
 extern int mkfifoat(int, const char *, mode_t);
 extern int mknodat(int, const char *, mode_t, dev_t);
 extern int fchmodat(int, const char *, mode_t, int);
+#endif
+
+#if defined(_XPG7) || !defined(_STRICT_SYMBOLS)
 extern int futimens(int, const struct timespec[2]);
 extern int utimensat(int, const char *, const struct timespec[2], int);
-#endif  /* defined(__EXTENSIONS__) ... */
-
-#else /* !__STDC__ */
-
-#if !defined(__XOPEN_OR_POSIX) || (_POSIX_C_SOURCE > 2) || \
-        defined(_XPG4_2) || defined(__EXTENSIONS__)
-extern int fchmod();
-#endif /* !defined(__XOPEN_OR_POSIX) || (_POSIX_C_SOURCE > 2)... */
-
-extern int chmod();
-extern int mkdir();
-extern int mkfifo();
-extern mode_t umask();
-
-/* transitional large file interfaces */
-#if     defined(_LARGEFILE64_SOURCE) && !((_FILE_OFFSET_BITS == 64) && \
-            !defined(__PRAGMA_REDEFINE_EXTNAME))
-extern int fstat64();
-extern int stat64();
-extern int lstat64();
-#if !defined(__XOPEN_OR_POSIX) || defined(__EXTENSIONS__) || \
-        defined(_ATFILE_SOURCE)
-extern int fstatat64();
-#endif /* defined (_ATFILE_SOURCE) */
 #endif
 
-#if defined(__EXTENSIONS__) || defined(_ATFILE_SOURCE) || \
-        (!defined(_STRICT_STDC) && !defined(__XOPEN_OR_POSIX))
-        /* || defined(_XPG7) */
-extern int mkdirat();
-extern int mkfifoat();
-extern int mknodat();
-extern int fchmodat();
-extern int futimens();
-extern int utimensat();
-#endif  /* defined(__EXTENSIONS__) ... */
-
-#endif /* defined(__STDC__) */
-
 #include <sys/stat_impl.h>
 
 #endif /* !defined(_KERNEL) */
 
 #ifdef  __cplusplus