[Libguestfs] [PATCH common 0/4] mltools: Introduce priority for ordering actions

https://bugzilla.redhat.com/show_bug.cgi?id=1953286#c26 This set of changes enhances the common/mltools On_exit module to: - allow actions to be ordered using a priority field - allow waiting for killed subprocesses to exit (with some caveats) Related set of changes to virt-v2v will follow. This will require some changes to libguestfs and guestfs-tools projects which I have not done yet because I want to get feedback on the approach first. Rich.