Move some definitions and add something private

definitions from asyncqueue to asyncprotocol to reduce dependency loops
add protocol-private data structure and killer routine

asyncprotocol.h

@@ -26,6 +26,12 @@ typedef enum {
   ATX_DISCO = 3
 } ATX_STATUS;
 
+#define AQU_TIMEOUT     -1
+#define AQU_DISCONNECT  -2
+#define AQU_RECONNECT   -3
+#define AQU_RETRY_CMD   -4
+#define AQU_POP_CMD     -5
+
 struct __async_txn {
   pAsyncUnit unit;  /**< unit that transaction is associated with */
   int txn_state;         /**< protocol handler transaction parse state */
@@ -38,6 +44,8 @@ struct __async_txn {
   int inp_len;         /**< length of input buffer */
   int inp_idx;         /**< index of next character (number already received) */
   AsyncTxnHandler handleResponse; /**< Txn response handler of command sender */
+  void *proto_private; /**< Protocol Private structure */
+  void (*kill_private) (struct __async_txn *pTxn); /**< if it needs killing */
   void *cntx;       /**< opaque context used by command sender */
   /* The cntx field may be used by protocol handler from sendCommand
    * as long as it is restored when response is complete