Thingsboard-gateway

ThingsBoard IoT gateway minor release, includes fixes and improvements for:
- MQTT connector;
- Modbus Connector;
- OPC-UA connector (Thanks joerg555);
- TB updater fixes;
- TB Gateway service fixes and improvements;

Additional features:
- If no connectors in connectors section in *tb_gateway.yaml* file - the gateway automatically turns on remote configuration and you are able to configure it from Gateways dashboard on ThingsBoard.
- **qos** parameter in general configuration (Quality of service for connection between the gateway and ThingsBoard instance, supported values - at most once **0** or at least once **1**)

**Main features**
- [SNMP Connector] Add ability to get information from SNMP manager.
- [Remote shell] Add ability to get access to the device shell from ThingsBoard UI.

**Additional features:**
- Optimized dependencies.

**Bug fixes:**
- Fix for RPC
- Fix for REST Connector
- Fix for Modbus Connector
- Some minor fixes.

**Additional features:**
- [BLE Connector] Added address type configuration parameter 334

**Bug fixes:**
- Fix for RPC calls after auto-reconnect to ThingsBoard
- Fix for auto-reconnect to MQTT broker
- Fix 320
- Fix for 318
- Fix for Docker image
- Fix for package generation script

Minor release with the following improvements.

**Main features:**
* [REST Connector] Added REST Connector to create your own endpoints and process the HTTP messages.

**Improvements:**
* [ODBC Connector] Improvements and tests.
* [CAN connector] Improvements and tests.
* [TB Utility] Installation improvements.

**Bug fixes:**
* [ODBC Connector] Fixes.
* [CAN Connector] Fixes.
* [TB Gateway Service] RPC command processing fixes.

Minor release with the following improvements.

**Improvements:**
* [OPC-UA Connector] Minor improvements

Minor release with the following improvements.

**Additional features:**
* [Auto-update notifier] Checking for new version is included in the gateway. If the new version will be available, you will know about it from logs.
* [RPC update request] To update your gateway just send RPC requests "gateway_update" and "gateway_restart" from TB to the gateway

**Improvements:**
* [MQTT Connector] Added ability to use JSON-Path Expressions as attribute/telemetry key. Found value will be used as a key on ThingsBoard.

**Bug fixes:**
* [Storage] Major fix in the storage.
* Some fixes.