Let TripwireHook be attachable. Addresses BUKKIT-2278

This commit also makes TripwireHook consistent with other attachables
for the facing property.

By: Wesley Wolfe <weswolf@aol.com>

paper-api/src/main/java/org/bukkit/material/TripwireHook.java

@@ -6,7 +6,7 @@ import org.bukkit.block.BlockFace;
 /**
  * Represents the tripwire hook
  */
-public class TripwireHook extends MaterialData implements Directional, Redstone {
+public class TripwireHook extends SimpleAttachableMaterialData implements Redstone {
 
     public TripwireHook() {
         super(Material.TRIPWIRE_HOOK);
@@ -68,24 +68,23 @@ public class TripwireHook extends MaterialData implements Directional, Redstone
     public void setFacingDirection(BlockFace face) {
         int dat = getData() & 0xC;
         switch (face) {
-            case EAST:
+        case NORTH:
-                break;
-            case SOUTH:
             dat |= 0x1;
             break;
-            case WEST:
+        case EAST:
             dat |= 0x2;
             break;
-            case NORTH:
+        case SOUTH:
             dat |= 0x3;
             break;
+        case WEST:
         default:
             break;
         }
         setData((byte) dat);
     }
 
-    public BlockFace getFacing() {
+    public BlockFace getAttachedFace() {
         switch (getData() & 0x3) {
         case 0:
             return BlockFace.EAST;