Fix Craft Entity constructors and toStrings.

Also, standardise getHandle and clean up in general.
getHandle is now using the 'entity' member variable instead of
super.getHandle, as this reduces the number of chained calls needed.

src/main/java/org/bukkit/craftbukkit/entity/CraftBoat.java

@@ -5,47 +5,50 @@ import org.bukkit.craftbukkit.CraftServer;
 import org.bukkit.entity.Boat;
 
 public class CraftBoat extends CraftVehicle implements Boat {
-    protected EntityBoat boat;
 
     public CraftBoat(CraftServer server, EntityBoat entity) {
         super(server, entity);
-        boat = entity;
     }
 
     public double getMaxSpeed() {
-        return boat.maxSpeed;
+        return getHandle().maxSpeed;
     }
 
     public void setMaxSpeed(double speed) {
         if (speed >= 0D) {
-            boat.maxSpeed = speed;
+            getHandle().maxSpeed = speed;
         }
     }
 
     public double getOccupiedDeceleration() {
-        return boat.occupiedDeceleration;
+        return getHandle().occupiedDeceleration;
     }
 
     public void setOccupiedDeceleration(double speed) {
         if (speed >= 0D) {
-            boat.occupiedDeceleration = speed;
+            getHandle().occupiedDeceleration = speed;
         }
     }
 
     public double getUnoccupiedDeceleration() {
-        return boat.unoccupiedDeceleration;
+        return getHandle().unoccupiedDeceleration;
     }
 
     public void setUnoccupiedDeceleration(double speed) {
-        boat.unoccupiedDeceleration = speed;
+        getHandle().unoccupiedDeceleration = speed;
     }
 
     public boolean getWorkOnLand() {
-        return boat.landBoats;
+        return getHandle().landBoats;
     }
 
     public void setWorkOnLand(boolean workOnLand) {
-        boat.landBoats = workOnLand;
+        getHandle().landBoats = workOnLand;
+    }
+
+    @Override
+    public EntityBoat getHandle() {
+        return (EntityBoat) entity;
     }
 
     @Override