Switch to Gradle. Use git log --follow for history.

This converts the project into a multi-module Gradle build.

By default, Git does not show history past a rename, so use git log
--follow to see further history.

worldedit-core/src/main/java/com/sk89q/worldedit/extent/ChangeSetExtent.java

@@ -0,0 +1,134 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.extent;
+
+import com.sk89q.worldedit.Vector;
+import com.sk89q.worldedit.WorldEditException;
+import com.sk89q.worldedit.blocks.BaseBlock;
+import com.sk89q.worldedit.entity.BaseEntity;
+import com.sk89q.worldedit.entity.Entity;
+import com.sk89q.worldedit.history.change.BlockChange;
+import com.sk89q.worldedit.history.change.EntityCreate;
+import com.sk89q.worldedit.history.change.EntityRemove;
+import com.sk89q.worldedit.history.changeset.ChangeSet;
+import com.sk89q.worldedit.regions.Region;
+import com.sk89q.worldedit.util.Location;
+
+import javax.annotation.Nullable;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Stores changes to a {@link ChangeSet}.
+ */
+public class ChangeSetExtent extends AbstractDelegateExtent {
+
+    private final ChangeSet changeSet;
+
+    /**
+     * Create a new instance.
+     *
+     * @param extent the extent
+     * @param changeSet the change set
+     */
+    public ChangeSetExtent(Extent extent, ChangeSet changeSet) {
+        super(extent);
+        checkNotNull(changeSet);
+        this.changeSet = changeSet;
+    }
+
+    @Override
+    public boolean setBlock(Vector location, BaseBlock block) throws WorldEditException {
+        BaseBlock previous = getBlock(location);
+        changeSet.add(new BlockChange(location.toBlockVector(), previous, block));
+        return super.setBlock(location, block);
+    }
+
+    @Nullable
+    @Override
+    public Entity createEntity(Location location, BaseEntity state) {
+        Entity entity = super.createEntity(location, state);
+        if (state != null) {
+            changeSet.add(new EntityCreate(location, state, entity));
+        }
+        return entity;
+    }
+
+    @Override
+    public List<? extends Entity> getEntities() {
+        return wrapEntities(super.getEntities());
+    }
+
+    @Override
+    public List<? extends Entity> getEntities(Region region) {
+        return wrapEntities(super.getEntities(region));
+    }
+
+    private List<? extends Entity> wrapEntities(List<? extends Entity> entities) {
+        List<Entity> newList = new ArrayList<Entity>(entities.size());
+        for (Entity entity : entities) {
+            newList.add(new TrackedEntity(entity));
+        }
+        return newList;
+    }
+
+    private class TrackedEntity implements Entity {
+        private final Entity entity;
+
+        private TrackedEntity(Entity entity) {
+            this.entity = entity;
+        }
+
+        @Override
+        public BaseEntity getState() {
+            return entity.getState();
+        }
+
+        @Override
+        public Location getLocation() {
+            return entity.getLocation();
+        }
+
+        @Override
+        public Extent getExtent() {
+            return entity.getExtent();
+        }
+
+        @Override
+        public boolean remove() {
+            Location location = entity.getLocation();
+            BaseEntity state = entity.getState();
+            boolean success = entity.remove();
+            if (state != null && success) {
+                changeSet.add(new EntityRemove(location, state));
+            }
+            return success;
+        }
+
+        @Nullable
+        @Override
+        public <T> T getFacet(Class<? extends T> cls) {
+            return entity.getFacet(cls);
+        }
+    }
+}