2.15.3rc

Caveat: Please note that this is a snapshot of a development branch, and most likely not anything like the actual 2.15.3 release. It may still contain bugs and shouldn't be considered production-ready. Also note that while this has been labeled as 2.15.3rc, it identifies itself as "Purr Data 2.15.2-20201015-rev.bd6f44e4".

This snapshot has been built from rev. bd6f44e and contains some of Ico's experimental bugfixes and changes which still need some testing, specifically MR 579, 587, and 590.