Update README

Author: chenshuo

README

@@ -1,13 +1,26 @@
 Muduo is a multithreaded C++ network library based on
 the reactor pattern.
-It runs on Linux with kernel version >= 2.6.28.
-http://code.google.com/p/muduo/
+
+http://github.com/chenshuo/muduo
 
 Copyright (c) 2010, Shuo Chen.  All rights reserved.
 
 Use of this source code is governed by a BSD-style
 license that can be found in the License file.
 
+Requires:
+  Linux kernel version >= 2.6.28.
+  GCC >= 4.7 or Clang >= 3.5
+  Boost (for boost::any only.)
+
+Tested on:
+  Debian 7 and above
+  Unbuntu 14.04 and above
+  CentOS 7 and above
+
+To build, run:
+  ./build.sh
+
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