(feature) Allow partial update of releases in output file.

[hastebrot]

TL;DR: The plan is to have the Gradle tasks createReleaseNotes and updateReleaseNotes. The former a complete creation for all releases, the latter a partial update for the latest releases.

The Problem

We generate release notes and put them into output files like CHANGES.md. These files contain releases, which are the basic building blocks and listed in reverse chronological order.

There are two parts that can be modified for partial updates:

• output file: use existing output file and add new releases to the top.
• network traffic: only fetch data related to new releases.