Anjay 3.10.0

Features

• Instruction how to generate packages for Anjay Demo was added to documentation.
• Dropped support for Ubuntu 18.04 and removed tests for it.

Bugfixes

• Fixed devconfig script which was incorrectly setting Anjay version in logs
  to "unknown".
• Added canceling the Register or Update message exchange if it's in progress
  when Server Disable (with resource execution or by API) is called that could
  have led to disabling the server infinitely.

Improvements

• Unified script for generating packages in integration tests, now it can also
  be used to generate packages for the Software Management object.
• The format of the metadata for packages used in integration tests and the
  demo has been revised to be more unambiguous and unified.
• Added confirmable_notification_status_cb handler that is called if
  acknowledgement for confirmable notification is received from the Server or
  some error has occurred.