NtfLog plugin

First release: Commands: /getblocklog - Gets the log of changes for the last location a block was placed /rollbackregion - rolls back the changes of a user over an area defined by two block placements /redoregionblockchanges - redoes the changes of a user over an area defined by two block placements

For memory efficiency, only about 10 changes will be kept for any particular block.*

The rollback and redo can make mistakes.

• The number recorded can actually be a bit higher than 10, since the ceiling for a deletion operation is actually 14 changes. In other words, the system won't actually delete any recorded changes until there are 14 or more changes for a particular block.