Added a magnitiude addition helper function.

src/main/java/ca/recrown/islandsurvivalcraft/Utilities.java

@@ -18,4 +18,11 @@ public class Utilities {
         }
         return res;
     }
+
+    public static int addMagnitude(int value, int add) {
+        boolean negative = false;
+        if (value < 0) negative = true;
+        int res = Math.abs(value) + add;
+        return negative ? - res : res;
+    }
 }