doc: update copyright years to 2012 stable

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 :-)

--- a/contrib/win32/ReadMe.html	Mon Apr 30 11:51:24 2012 +0200
+++ b/contrib/win32/ReadMe.html	Mon Apr 30 12:04:30 2012 +0200
@@ -140,7 +140,7 @@
     </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>
 

--- a/doc/hg.1.txt	Mon Apr 30 11:51:24 2012 +0200
+++ b/doc/hg.1.txt	Mon Apr 30 12:04:30 2012 +0200
@@ -112,7 +112,7 @@
 
 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.
 

--- a/doc/hgignore.5.txt	Mon Apr 30 11:51:24 2012 +0200
+++ b/doc/hgignore.5.txt	Mon Apr 30 12:04:30 2012 +0200
@@ -26,7 +26,7 @@
 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.
 

--- a/doc/hgrc.5.txt	Mon Apr 30 11:51:24 2012 +0200
+++ b/doc/hgrc.5.txt	Mon Apr 30 12:04:30 2012 +0200
@@ -34,7 +34,7 @@
 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.