We'd like to integrate the support for pre-defined sets of paths for INSTALL_MASK in portage. For this reason, we'd like to allow repositories to define their own sets of INSTALL_MASK sets. The idea of the file is quite simple -- it lists names and attaches a lists of paths to them, much like thirdpartymirrors. It may be also useful to add descriptions to the names. The format is of your choice. I think that the file should be covered in PMS. It's an additional file for an optional feature so it doesn't need to be EAPI-aware. Any thoughts?
