Vere urth/mars restage (discussion issue)

[eamsden]

Several integration issues between Vere and Ares would be solved by migrating both to the urth/mars protocol instead of the current king/serf protocol. In particular, Vere forgoes the serf protocol for many subcommands and simply directly loads the snapshot (as well as the event log.) Making all such subcommands the responsibility of mars would allow a cleaner separation between ares-mars and vere-mars than is possible between ares-serf and vere-serf.