Patch for <features.h> comments

[Daniel Jacobowitz <drow at false dot org>]

While looking through <features.h> I got a bit confused by the comments
at the top, and cleaned them up a little.  Is this correct?

Dan

/--------------------------------\  /--------------------------------\
|       Daniel Jacobowitz        |__|        SCS Class of 2002       |
|   Debian GNU/Linux Developer    __    Carnegie Mellon University   |
|         dan@debian.org         |  |       dmj+@andrew.cmu.edu      |
\--------------------------------/  \--------------------------------/
*** /usr/include/features.h	Wed Sep 29 08:17:03 1999
--- features.h	Sat Dec 18 15:28:38 1999
***************
*** 31,53 ****
     _XOPEN_SOURCE	Includes POSIX and XPG things.  Set to 500 if
  			Single Unix conformance is wanted.
     _XOPEN_SOURCE_EXTENDED XPG things and X/Open Unix extensions.
-    _LARGEFILE_SOURCE	Some more functions for correct standard I/O.
-    _LARGEFILE64_SOURCE	Additional functionality from LFS for large files.
-    _FILE_OFFSET_BITS=N	Select default filesystem interface.
     _BSD_SOURCE		ISO C, POSIX, and 4.3BSD things.
     _SVID_SOURCE		ISO C, POSIX, and SVID things.
!    _GNU_SOURCE		All of the above, plus GNU extensions.
!    _REENTRANT		Select additionally reentrant object.
!    _THREAD_SAFE		Same as _REENTRANT, often used by other systems.
  
     The `-ansi' switch to the GNU C compiler defines __STRICT_ANSI__.
!    If none of these are defined, the default is all but _GNU_SOURCE.
!    If more than one of these are defined, they accumulate.
     For example __STRICT_ANSI__, _POSIX_SOURCE and _POSIX_C_SOURCE
     together give you ISO C, 1003.1, and 1003.2, but nothing else.
  
     These are defined by this file and are used by the
!    header files to decide what to declare or define:
  
     __USE_ISOC9X		Define ISO C 9X things.
     __USE_POSIX		Define IEEE Std 1003.1 things.
--- 31,58 ----
     _XOPEN_SOURCE	Includes POSIX and XPG things.  Set to 500 if
  			Single Unix conformance is wanted.
     _XOPEN_SOURCE_EXTENDED XPG things and X/Open Unix extensions.
     _BSD_SOURCE		ISO C, POSIX, and 4.3BSD things.
     _SVID_SOURCE		ISO C, POSIX, and SVID things.
!    _GNU_SOURCE		All of the above, plus _LARGEFILE64_SOURCE and
! 			GNU extensions.
  
     The `-ansi' switch to the GNU C compiler defines __STRICT_ANSI__.
!    If none of these are defined, the default is all of the above but
!    _GNU_SOURCE.  If more than one of these are defined, they accumulate.
     For example __STRICT_ANSI__, _POSIX_SOURCE and _POSIX_C_SOURCE
     together give you ISO C, 1003.1, and 1003.2, but nothing else.
  
+    These can also be defined by the user (or compiler):
+ 
+    _LARGEFILE_SOURCE	Some more functions for correct standard I/O.
+    _LARGEFILE64_SOURCE	Additional functionality from LFS for large files.
+    _FILE_OFFSET_BITS=N	Select default filesystem interface.
+    _REENTRANT		Select additionally reentrant object.
+    _THREAD_SAFE		Same as _REENTRANT, often used by other systems.
+ 
     These are defined by this file and are used by the
!    header files to decide what to declare or define,
!    and should not be defined by the user or compiler:
  
     __USE_ISOC9X		Define ISO C 9X things.
     __USE_POSIX		Define IEEE Std 1003.1 things.