immer

Getters and setters are now handled consistently: own getters and setters will always by copied into fields (like Object.assign does), inherited getters and setters will be left as-is. This should allow using Immer directly on objects that trap their fields, like done in Vue or MobX. Fixes #584, #439, #593, #558

Produce no longer accepts non-draftable objects as first argument

Original can only be called on drafts and will throw otherwise (fixes #605)

non-enumerable and symbolic fields will never be frozen

The patches for arrays are now computed differently to fix some scenarios in which they were incorrect. In some cases they will be more optimal now, in other cases less. Especially splicing / unshifting items into an existing array might result in a lot of patches. Fixes #468