doc: update copyright years to 2012

I sometimes look at a piece of software and if the man page says
"Copyright 2004", then I'm inclined to think that the project is stale
or that the authors are lazy. Neither is good publicity for us :-)

contrib/win32/ReadMe.html

@@ -140,7 +140,7 b' editor = whatever'
     </p>
 
     <p>
-      Mercurial is Copyright 2005-2010 Matt Mackall and others. See
+      Mercurial is Copyright 2005-2012 Matt Mackall and others. See
       the <tt>Contributors.txt</tt> file for a list of contributors.
     </p>
 

doc/hg.1.txt

@@ -112,7 +112,7 b' Mailing list: http://selenic.com/mailman'
 
 Copying
 -------
-Copyright (C) 2005-2010 Matt Mackall.
+Copyright (C) 2005-2012 Matt Mackall.
 Free use of this software is granted under the terms of the GNU General
 Public License version 2 or any later version.
 

doc/hgignore.5.txt

@@ -26,7 +26,7 b' See Also'
 Copying
 -------
 This manual page is copyright 2006 Vadim Gelfer.
-Mercurial is copyright 2005-2010 Matt Mackall.
+Mercurial is copyright 2005-2012 Matt Mackall.
 Free use of this software is granted under the terms of the GNU General
 Public License version 2 or any later version.
 

doc/hgrc.5.txt

@@ -34,7 +34,7 b' See Also'
 Copying
 -------
 This manual page is copyright 2005 Bryan O'Sullivan.
-Mercurial is copyright 2005-2010 Matt Mackall.
+Mercurial is copyright 2005-2012 Matt Mackall.
 Free use of this software is granted under the terms of the GNU General
 Public License version 2 or any later version.