Changes in this update:
**Enhancements**
* Added the `ExternalMediaPlayer` Capability Agent. This allows playback from music providers that control their own playback queue. Example: Spotify.
* Added support for AU and NZ to the `SampleApp`.
* Firmware version can now be sent to Alexa via the `SoftwareInfo` event. The firmware version is specified in the config file under the `sampleApp` object as an integer value named [`firmwareVersion`](https://github.com/alexa/avs-device-sdk/blob/master/Integration/AlexaClientSDKConfig.json#L52).
* The new `f` command was added to the `SampleApp` which allows the firmware version to be updated at run-time.
* Optional configuration changes have been introduced. Now a [default log level](https://github.com/alexa/avs-device-sdk/blob/master/Integration/AlexaClientSDKConfig.json#L93) can be set for `ACSDK_LOG_MODULE` components, globally or individually. This value is specified under a new root level configuration object called `logger`, and the value itself is named `logLevel`. This allows you to limit the degree of logging to that default value, such as `ERROR`or `INFO`.
**Bug Fixes**
* Fixed bug where `AudioPlayer` progress reports were not being sent, or were being sent incorrectly.
* [Issue 408](https://github.com/alexa/avs-device-sdk/issues/408) - Irrelevant code related to `UrlSource` was removed from the `GStreamer-based MediaPlayer` implementation.
* The `TZ` variable no longer needs to be set to `UTC` when building the `SampleApp`.
* Fixed a bug where `CurlEasyHandleWrapper` logged unwanted data on failure conditions.
* Fixed a bug to improve `SIGPIPE` handling.
* Fixed a bug where the filename and classname were mismatched. Changed `UrlToAttachmentConverter.h` to `UrlContentToAttachmentConverter.h`,and `UrlToAttachmentConverter.cpp` to `UrlContentToAttachmentConverter.cpp`
**Known Issues**
* The `ACL` may encounter issues if audio attachments are received but not consumed.
* Display Cards for Kindle don't render.
* If using the GStreamer-based `MediaPlayer` implementation, after muting and un-muting an audio item, the next item in the queue will begin playing rather than continuing playback of the originally muted audio item.
* `SpeechSynthesizerState` currently uses `GAINING_FOCUS` and `LOSING_FOCUS` as a workaround for handling intermediate state. These states may be removed in a future release.
* Music playback doesn't immediately stop when a user barges-in on iHeartRadio.
Changes in this update
* **Enhancements**..
* Added comments to `AlexaClientSDKConfig.json`. These descriptions provide additional guidance for what is expected for each field...
* Enabled pause and resume controls for Pandora...
* **Bug Fixes**..
* Bug fix for [issue #329](https://github.com/alexa/avs-device-sdk/issues/329) - `HTTP2Transport` instances no longer leak when `SERVER_SIDE
* Bug fix for [issue #189](https://github.com/alexa/avs-device-sdk/issues/189) - Fixed a race condition in the `Timer` class that sometimes
* Bug fix for a race condition that caused `SpeechSynthesizer` to ignore subsequent `Speak` directives...
* Bug fix for corrupted mime attachments.