I've finally gotten around to testing and integrating a bunch of work on RCC++ which I've had on my development fork for a while. The main feature was requested by the team behind Kythera AI (previously Intelligent Artefacts and now Moon Collider) who've been sponsoring much of the recent work on RCC++. They've found that it would be beneficial to be able to set compile options such as include and library paths on a per-module basis, so we've introduced a feature called 'Projects'. Read more about that on our wiki page for Using ProjectIds and Projects.
For the complete list of changes, see the pull request.