Fix MaterialData directions being incorrect. Fixes BUKKIT-3160

Prior to 49690f9, BlockFaces were mostly correct in their respective
MaterialData classes. However, a lot of things were not updated since
implementation and broke without being addressed.

This fixes any discrepancies with Block data.

By: feildmaster <admin@feildmaster.com>

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

@@ -77,16 +77,16 @@ public class Rails extends MaterialData {
             return BlockFace.SOUTH;
 
         case 0x6:
-            return BlockFace.NORTH_EAST;
+            return BlockFace.NORTH_WEST;
 
         case 0x7:
-            return BlockFace.SOUTH_EAST;
+            return BlockFace.NORTH_EAST;
 
         case 0x8:
-            return BlockFace.SOUTH_WEST;
+            return BlockFace.SOUTH_EAST;
 
         case 0x9:
-            return BlockFace.NORTH_WEST;
+            return BlockFace.SOUTH_WEST;
         }
     }
 
@@ -132,19 +132,19 @@ public class Rails extends MaterialData {
             setData((byte) (isOnSlope ? 0x5 : 0x0));
             break;
 
-        case NORTH_EAST:
+        case NORTH_WEST:
             setData((byte) 0x6);
             break;
 
-        case SOUTH_EAST:
+        case NORTH_EAST:
             setData((byte) 0x7);
             break;
 
-        case SOUTH_WEST:
+        case SOUTH_EAST:
             setData((byte) 0x8);
             break;
 
-        case NORTH_WEST:
+        case SOUTH_WEST:
             setData((byte) 0x9);
             break;
         }