update AUTHORS

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@2570 bbd45198-f89e-11dd-88c7-29a3b14d5316

AUTHORS

 Kernel Design & Implementation
 - Bernard Xiong <bernard.xiong@gmail.com>
 
-LwIP 1.3.0/1.3.1/1.3.2
+LwIP 1.3.0/1.3.1/1.3.2/1.4.0
 - Porting
   Qiu Yi
+  Mbbill
 - Testing
   Bernard Xiong
 
@@ -11,10 +12,12 @@ Filesystem
 - Porting and Add Virtual Filesystem
 - Testing
   Qiu Yi
+  prife
 
 RTGUI
 - Design and Implemenation
   Bernard Xiong
+  Grissiom
 
 BSP
 Bernard Xiong