Cache some parts of the game
[performance] Cache player extension.
[performance] Do not reload player if it is current player.
[performance] Cache ArtifactGroup for god calls - custom level.
[performance] Context processors and apps (refactor)
Fix test in performance branch.
[performance] Qotd: Do not set question if we don't have one (the update is expensive)
[performance] Cache quest get_current (very expensive call).
[performance] Do not query user again in challenge.
[performance] Do not query user again in messages.
Fix a test with coin.name instead of coin.id