Add JSON Library for serializing

src/main/java/org/json/JSONString.java

@@ -0,0 +1,18 @@
+package org.json;
+/**
+ * The <code>JSONString</code> interface allows a <code>toJSONString()</code>
+ * method so that a class can change the behavior of
+ * <code>JSONObject.toString()</code>, <code>JSONArray.toString()</code>,
+ * and <code>JSONWriter.value(</code>Object<code>)</code>. The
+ * <code>toJSONString</code> method will be used instead of the default behavior
+ * of using the Object's <code>toString()</code> method and quoting the result.
+ */
+public interface JSONString {
+    /**
+     * The <code>toJSONString</code> method allows a class to produce its own JSON
+     * serialization.
+     *
+     * @return A strictly syntactically correct JSON text.
+     */
+    public String toJSONString();
+}