Changed the Subversion README to Mercurial.

--HG--
rename : README.SVN => README.HG

README.SVN → README.HG

 
-The latest development version of SDL is available via Subversion.
-Subversion allows you to get up-to-the-minute fixes and enhancements;
-as a developer works on a source tree, you can use svn to mirror that
+The latest development version of SDL is available via Mercurial.
+Mercurial allows you to get up-to-the-minute fixes and enhancements;
+as a developer works on a source tree, you can use "hg" to mirror that
 source tree instead of waiting for an official release. Please look
-at the Subversion website ( http://subversion.tigris.org/ ) for more
-information on using svn, where you can also download software for
-MacOS, Windows, and Unix systems.
+at the Mercurial website ( http://mercurial.selenic.com/ ) for more
+information on using hg, where you can also download software for
+Mac OS X, Windows, and Unix systems.
 
-  svn checkout http://svn.libsdl.org/trunk/SDL
+  hg clone http://hg.libsdl.org/SDL
 
 If you are building SDL with an IDE, you will need to copy the file
 include/SDL_config.h.default to include/SDL_config.h before building.
@@ -16,7 +16,7 @@ If you are building SDL via configure, you will need to run autogen.sh
 before running configure.
 
 There is a web interface to the subversion repository at:
-	http://www.libsdl.org/cgi/viewvc.cgi
+	http://hg.libsdl.org/SDL/
 
 There is an RSS feed available at that URL, for those that want to
 track commits in real time.