修复CPU占用问题，添加servers.JOIN,LEAVE,LIST包

proto/server.proto

@@ -7,6 +7,9 @@ enum ServerPacketType {
   NEW = 2;
   DELETE = 3;
   CONNECT = 4;
+  JOIN = 5;
+  LEAVE = 6;
+  LIST = 7;
 }
 
 message ServerPacket {
@@ -30,4 +33,13 @@ message ServerDeletePacket {
 message ServerConnectPacket {
   string serverId = 1;
   string player = 2;
+}
+
+message ServerPlayerPacket {
+  string player = 1;
+}
+
+message ServerListPacket {
+  string serverId = 1;
+  repeated string players = 2;
 }