add ota algorithm for device

1. effective "Differential Upgrade" patch algorithm with high compression rate
2. effective recovery algorithm support recovery firmware in blocks which has low memory consumption and wear-leveling strategies, especially suitable for embeded devices with low RAM.
3. add sample ota bootloader project, see:
board\TencentOS_tiny_EVB_MX_Plus\KEIL\ota\ota_bootloader_recovery
4. add sample application project for download firmware through http, see:
board\TencentOS_tiny_EVB_MX_Plus\KEIL\ota\ota_application_download_through_http
5. add sample application project for download firmware through qcloud explorer console, see:
board\TencentOS_tiny_EVB_MX_Plus\KEIL\ota\ota_application_download_through_qcloud_iot_explorer
6. an OTA markdown document is pending

components/ota/common/lzma/3rdparty/XzCrc64.h

@@ -0,0 +1,26 @@
+/* XzCrc64.h -- CRC64 calculation
+2013-01-18 : Igor Pavlov : Public domain */
+
+#ifndef __XZ_CRC64_H
+#define __XZ_CRC64_H
+
+#include <stddef.h>
+
+#include "7zTypes.h"
+
+EXTERN_C_BEGIN
+
+extern UInt64 g_Crc64Table[];
+
+void MY_FAST_CALL Crc64GenerateTable(void);
+
+#define CRC64_INIT_VAL UINT64_CONST(0xFFFFFFFFFFFFFFFF)
+#define CRC64_GET_DIGEST(crc) ((crc) ^ CRC64_INIT_VAL)
+#define CRC64_UPDATE_BYTE(crc, b) (g_Crc64Table[((crc) ^ (b)) & 0xFF] ^ ((crc) >> 8))
+
+UInt64 MY_FAST_CALL Crc64Update(UInt64 crc, const void *data, size_t size);
+UInt64 MY_FAST_CALL Crc64Calc(const void *data, size_t size);
+
+EXTERN_C_END
+
+#endif