Make operations atomic and undoable

Currently most operations when they fail make no attempt to revert the state of what was changed to be as it was before the operation was made. I propose making operations so that they have a "do()" "revert()" and "errorRevert()" where errors can be handled gracefully.

• Create a base implementation
• Convert the extractor to an operation
• • Without undo()
• • Add undo() functionality (requires folder/file deletion)
• File/Folder creation/deletion
• • Deletion
• • Creation
• Folder/File coping/cutting
• • Copy/Cut
• • Undo
• Random bug squashing
• Documentation

No files, entry points, or tests are named. Start by locating the existing operation, extractor, and file/folder copy, cut, creation, and deletion implementations, then determine which listed atomic and undoable behaviors remain incomplete; done means failed operations restore their prior state and the related documentation is current.