Fix datatype.Scalar equals() and hashCode() methods

The previously used Number.equals() and hashCode() was just delegated
to Object and hence did not behave as expected.

smack-core/src/main/java/org/jivesoftware/smack/datatypes/Scalar.java

@@ -54,13 +54,29 @@ public abstract class Scalar extends java.lang.Number {
     }
 
     @Override
-    public final int hashCode() {
-        return number.hashCode();
-    }
+    public abstract int hashCode();
 
     @Override
-    public final boolean equals(Object other) {
-        return number.equals(other);
+    public boolean equals(Object other) {
+        if (!(other instanceof Scalar)) {
+            return false;
+        }
+
+        Scalar otherScalar = (Scalar) other;
+
+        if (longValue() == otherScalar.longValue()) {
+            return true;
+        }
+
+        if (doubleValue() == otherScalar.doubleValue()) {
+            return true;
+        }
+
+        if (floatValue() == otherScalar.floatValue()) {
+            return true;
+        }
+
+        return false;
     }
 
     @Override

smack-core/src/main/java/org/jivesoftware/smack/datatypes/UInt16.java

@@ -39,4 +39,19 @@ public final class UInt16 extends Scalar {
     public static UInt16 from(int number) {
         return new UInt16(number);
     }
+
+    @Override
+    public int hashCode() {
+        return number;
+    }
+
+    @Override
+    public boolean equals(Object other) {
+        if (other instanceof UInt16) {
+            UInt16 otherUint16 = (UInt16) other;
+            return number == otherUint16.number;
+        }
+
+        return super.equals(other);
+    }
 }

smack-core/src/main/java/org/jivesoftware/smack/datatypes/UInt32.java

@@ -39,4 +39,20 @@ public final class UInt32 extends Scalar {
     public static UInt32 from(long number) {
         return new UInt32(number);
     }
+
+    @Override
+    public int hashCode() {
+        // TODO: Use Long.hashCode(number) once Smack's minimum Android SDK level is 24 or higher.
+        return (int) (number ^ (number >>> 32));
+    }
+
+    @Override
+    public boolean equals(Object other) {
+        if (other instanceof UInt32) {
+            UInt32 otherUint32 = (UInt32) other;
+            return number == otherUint32.number;
+        }
+
+        return super.equals(other);
+    }
 }