Operation now has `editor` and `level` as required arguments to init. Operation has a default `undo` implementation that copies all chunks from `undoLevel`. `undoSchematic` renamed to `undoLevel`
Submodule pymclevel updated.
Submodule pymclevel:
> 07c8024 - BoundingBox: Made BoundingBox immutable and added immutable Vector class
> f5e4fd1 - FakeChunk now uses TAG_List for its fake Entities and TileEntities instead of lists.
> 3e4a9b8 - NBT: TAG_List now accepts item assignment using slices.
> 30cfb1d - Test: testFillBlocks calls fillBlocks with a blocksToReplace argument
> 3fb1b0c - Fixed: Scan the unsaved work folder and _loadedChunkData in addition to the world folder when listing chunks.
> fae5e61 - Fixed: Scan the unsaved work folder in addition to the world folder when listing chunks.
