Fix clang getting started guide to require VC2013 instead of VS2012.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@236733 91177308-0d34-0410-b5e6-96231b3b80d8

www/get_started.html

@@ -148,7 +148,7 @@ Visual Studio:</p>
         project files.  Get it from:
         <a href="http://www.cmake.org/cmake/resources/software.html">
         http://www.cmake.org/cmake/resources/software.html</a></li>
-    <li><b>Visual Studio 2012 or later</b></li>
+    <li><b>Visual Studio 2013 or later</b></li>
     <li><b>Python</b>.  This is needed only if you will be running the tests
         (which is essential, if you will be developing for clang).
         Get it from:
@@ -180,7 +180,7 @@ Visual Studio:</p>
     <li><tt>cd ..\..</tt>  (back to where you started)</li>
     <li><tt>mkdir build</tt> (for building without polluting the source dir)</li>
     <li><tt>cd build</tt></li>
-    <li>If you are using Visual Studio 2012:  <tt>cmake -G "Visual Studio 11" ..\llvm</tt></li>
+    <li>If you are using Visual Studio 2013:  <tt>cmake -G "Visual Studio 12" ..\llvm</tt></li>
     <li>See the <a href="http://www.llvm.org/docs/CMake.html">LLVM CMake guide</a> for
         more information on other configuration options for CMake.</li>
     <li>The above, if successful, will have created an LLVM.sln file in the