HISTORY.md newest position is called (unreleased)

When making a new release, HISTORY.md newest position is called (unreleased) instead of the newest version.

I've created a simple workaround by modifying release under Makefile.

Instead of calling:

@$(ENV_PREFIX)gitchangelog  > HISTORY.md

You could perhaps do something like:

@$(ENV_PREFIX)gitchangelog | sed "s/(unreleased)/$${TAG} ($$(date +%Y-%m-%d))/g" > HISTORY.md

Furthermore, you could get rid of all the release commits from changelog:

@$(ENV_PREFIX)gitchangelog | sed "s/(unreleased)/$${TAG} ($$(date +%Y-%m-%d))/g" | grep -v "Release: version" > HISTORY.md

This way HISTORY.md contains relevant commits only.