moved readconsoleinputstream to samples folder; added readme; updated root readme.

samples/ReadConsoleInputStream/NativeMethods.cs

@@ -0,0 +1,31 @@
+using System;
+using System.Diagnostics;
+using System.Runtime.InteropServices;
+
+namespace Samples.Terminal
+{
+    internal static class NativeMethods
+    {
+        private static int MakeHRFromErrorCode(int errorCode)
+        {
+            // Don't convert it if it is already an HRESULT
+            if ((0xFFFF0000 & errorCode) != 0)
+            {
+                Debug.Assert(false, "errorCode is already HRESULT");
+                return errorCode;
+            }
+
+            return unchecked(((int)0x80070000) | errorCode);
+        }
+
+        internal static Exception GetExceptionForWin32Error(int errorCode)
+        {
+            return Marshal.GetExceptionForHR(MakeHRFromErrorCode(errorCode));
+        }
+
+        internal static Exception GetExceptionForLastWin32Error()
+        {
+            return GetExceptionForWin32Error(Marshal.GetLastWin32Error());
+        }
+    }
+}