Reconsider removing v5 & v6

@nechvatalp @nechvatalp Please reconsider how you all have restructured this library. It just broke a ton of our stuff with removing v6 & v5 code. In the old structure the various versions lived side-by-side so I think it's a fair assumption that people used liberal version restrictions assuming that the library would follow that pattern and not suddenly drop v6 from the code entirely.

未指定檔案、測試或進入點。檢視移除了 v5 和 v6 程式碼的重構，然後確定是否能在不破壞現有版本限制的情況下恢復並列版本支援；完成表示已決定相容性方案及相應的實作範圍。