YANG sub module linking + unsupported yang construct + defect fix

Change-Id: I224c8c14ee2111f6844278cb540c48651544f59b
diff --git a/src/main/java/org/onosproject/yangutils/datamodel/YangBelongsTo.java b/src/main/java/org/onosproject/yangutils/datamodel/YangBelongsTo.java
index 7fd8a1a..417e07e 100644
--- a/src/main/java/org/onosproject/yangutils/datamodel/YangBelongsTo.java
+++ b/src/main/java/org/onosproject/yangutils/datamodel/YangBelongsTo.java
@@ -57,6 +57,11 @@
     private String belongsToModuleName;
 
     /**
+     * Module node to which sub-module belongs to.
+     */
+    private YangNode moduleNode;
+
+    /**
      * Reference RFC 6020.
      *
      * The mandatory "prefix" substatement assigns a prefix for the module to
@@ -110,6 +115,24 @@
     }
 
     /**
+     * Returns the module data model node.
+     *
+     * @return the module data model node
+     */
+    public YangNode getModuleNode() {
+        return moduleNode;
+    }
+
+    /**
+     * Sets the module node.
+     *
+     * @param moduleNode module data model node
+     */
+    public void setModuleNode(YangNode moduleNode) {
+        this.moduleNode = moduleNode;
+    }
+
+    /**
      * Returns the type of the data as belongs-to.
      *
      * @return ParsedDataType returns BELONGS_TO_DATA