merge new qcloud sdk

1. qcloud has a great revolution, the protocol has been changed to implement data template, so the old TencentCloud_SDK developed by us will not work fine now(mqtt still works, but data template will not works fine for recently created product/devices).

2. I merge the official qlcoud sdk(include both the iot-hub and iot-explorer sdk) into the componet/conectivity to support new protocol of data template

3. iot-hub sdk, supply the fundamental iot protocol(like mqtt coap, etc.)
iot-explorer sdk, supply the high level service like data template based on mqtt

4. To know how it works, see qcloud_iot_explorer_sdk_data_template、qcloud_iot_hub_sdk_mqtt example(keil project in board\TencentOS_tiny_EVB_MX_Plus\KEIL\qcloud_iot_explorer_sdk_data_template and  board\TencentOS_tiny_EVB_MX_Plus\KEIL\qcloud_iot_hub_sdk_mqtt)

components/connectivity/qcloud-iot-hub-sdk-3.1.2/3rdparty/sdk_src/utils/utils_ringbuff.c

@@ -0,0 +1,106 @@
+/*
+ * Tencent is pleased to support the open source community by making IoT Hub available.
+ * Copyright (C) 2019 THL A29 Limited, a Tencent company. All rights reserved.
+
+ * Licensed under the MIT License (the "License"); you may not use this file except in
+ * compliance with the License. You may obtain a copy of the License at
+ * http://opensource.org/licenses/MIT
+
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is
+ * distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+ * either express or implied. See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include "utils_ringbuff.h"
+
+int ring_buff_init(sRingbuff* ring_buff, char* buff, uint32_t size )
+{
+	ring_buff->buffer     = buff;
+    ring_buff->size       = size;
+    ring_buff->readpoint  = 0;
+    ring_buff->writepoint = 0;
+	memset(ring_buff->buffer, 0, ring_buff->size);
+	ring_buff->full = false;
+	
+    return RINGBUFF_OK;
+}
+
+int ring_buff_flush(sRingbuff* ring_buff)
+{
+    ring_buff->readpoint  = 0;
+    ring_buff->writepoint = 0;
+	memset(ring_buff->buffer, 0, ring_buff->size);
+	ring_buff->full = false;
+	
+    return RINGBUFF_OK;
+}
+
+int ring_buff_push_data(sRingbuff* ring_buff, uint8_t *pData, int len)
+{
+	int i;
+	
+	if(len > ring_buff->size)
+	{
+		return RINGBUFF_TOO_SHORT;
+	}
+
+	for(i = 0; i < len; i++)
+	{
+		if(((ring_buff->writepoint + 1) % ring_buff->size) == ring_buff->readpoint)
+	    {
+	    	ring_buff->full = true;
+	        return RINGBUFF_FULL;
+	    }
+	    else
+	    {
+	        if(ring_buff->writepoint < (ring_buff->size - 1)) 
+	        {
+				ring_buff->writepoint ++;
+			}         
+	        else
+	        {
+				ring_buff->writepoint = 0;
+			}	            
+			ring_buff->buffer[ring_buff->writepoint] = pData[i];
+	    } 		
+	}
+
+	return RINGBUFF_OK;
+}
+
+int ring_buff_pop_data(sRingbuff* ring_buff, uint8_t *pData, int len)
+{
+	int i;
+
+	if(len > ring_buff->size)
+	{
+		 return RINGBUFF_TOO_SHORT;
+	}
+
+	for(i = 0; i < len; i++)
+	{
+		if(ring_buff->writepoint == ring_buff->readpoint)
+		{
+			break;
+		}
+		else
+		{
+			if(ring_buff->readpoint == (ring_buff->size - 1))
+			{
+				ring_buff->readpoint = 0;				
+			}
+
+			else
+			{
+				ring_buff->readpoint++;
+			}
+			pData[i] = ring_buff->buffer[ring_buff->readpoint];
+		}
+	}
+	
+	return i;
+}