Clans: weekly donations that survive the reset

The Elixir Gym's second run over the clan tools. A player's weekly donations only go up until the game resets them to zero, so Elixir now takes a week's donations as the highest number it saw that week. A read just after the reset can no longer wipe the week out, which had zeroed two recent weeks for whole clans; those weeks are repaired to the best value on record. Clan standings filtered to casual or event play now count event battles correctly. Contract 6.33.0.