Iotc

Added

- Support for Offline Commands (aka C2D).
- New "samples" project
- Added "report" functions for property and commands (_ack_ and _reply_);

Changed
- Aligned naming convenction with IoTCentral UX ( e.g. Settings -> Properties)
- Improved types for Property and Command.
- Fixed loggers.


<!-- [2.0.0]: https://github.com/lucadruda/iotc-nodejs-device-client/compare/v1.0.0...v1.1.0 -->

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- added model_id to iothub connection string

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- added credentials cache serialize/deserialize methods
- added "Property" model
- added storage tests

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- minor fixes for value wrapping

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- dropped Python 2.7 support (client should continue to work without tests)
- added DTDLv2 Support (with components)
- added graceful shutdown
- added credentials cache
- added device twin synchronization at boot
- improved tests and coverage

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- fix property report with value wrapped