Add support of auto format files.

sources_non_forked/vim-autoformat/samples/csharp.cs

@@ -0,0 +1,4 @@
+using System; class Program { static int Main(string[] args) { Console.WriteLine(args[0]); int i = 0; i++; return 0; } 
+    public int Foo() { switch (1) { case 1: int i = 0; default: int j = 1; }
+    }
+}