Fixing javadoc warnings, provided missing package javadocs and corrected group structure.

Change-Id: I2637afe49b81e8e6d10ef3bb0f2a1cf50b2564cc
diff --git a/core/api/src/main/java/org/onosproject/ui/UiExtension.java b/core/api/src/main/java/org/onosproject/ui/UiExtension.java
index c310858..1f5fbd4 100644
--- a/core/api/src/main/java/org/onosproject/ui/UiExtension.java
+++ b/core/api/src/main/java/org/onosproject/ui/UiExtension.java
@@ -72,7 +72,7 @@
      * @return JavaScript inclusion statements
      */
     public InputStream js() {
-       return getStream(resourcePath + JS_HTML);
+        return getStream(resourcePath + JS_HTML);
     }
 
     /**
@@ -141,7 +141,8 @@
          * Views defaults to an empty list.
          * Both Message and TopoOverlay factories default to null.
          *
-         * @param cl the classloader
+         * @param cl    the class loader
+         * @param views list of views contributed by this extension
          */
         public Builder(ClassLoader cl, List<UiView> views) {
             checkNotNull(cl, "Must provide a class loader");
diff --git a/core/api/src/main/java/org/onosproject/ui/topo/package-info.java b/core/api/src/main/java/org/onosproject/ui/topo/package-info.java
new file mode 100644
index 0000000..85ac7fe
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/ui/topo/package-info.java
@@ -0,0 +1,21 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * Mechanism for dynamically extending topology view with information and
+ * behaviour overlays.
+ */
+package org.onosproject.ui.topo;
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