Also ignore Visual Studio 2013 files

Change-Id: I21bba16d70f9f8c43b60b2bd2a5005a888d0c11d
Reviewed-on: https://gerrit.libreoffice.org/14073Tested-by: Michael Stahl <mstahl@redhat.com>
Reviewed-by: Michael Stahl <mstahl@redhat.com>

.gitignore

@@ -99,6 +99,7 @@ xcuserdata
 *.sdf
 *.sln
 *.v11*
+*.v12*
 *.vcxproj*
 *.opensdf