Added a README file regarding WinRT support

To note, this file is currently formatted with CRLF line endings, rather than
LF, to allow the file to be viewed with Notepad.

premake/Xcode-iOS/build-scripts/xcode3.command

@@ -0,0 +1,4 @@
+#!/bin/sh
+# change to directory above command file
+cd `dirname $0`/..
+`dirname $0`/premake4 --file=../premake4.lua --to=./Xcode-iOS --ios xcode3