GUI -- added getAsString() to TableModel.Row.
- Moved cell-related classes to new package.
- Created base classes for cell comparator and formatter.
- Created IntComparator and HexFormatter.

Change-Id: I3861bf3e0ca738a2d6eab9c70174db53f22960f8
diff --git a/core/api/src/main/java/org/onosproject/ui/table/cell/HexFormatter.java b/core/api/src/main/java/org/onosproject/ui/table/cell/HexFormatter.java
new file mode 100644
index 0000000..d4aaade
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/ui/table/cell/HexFormatter.java
@@ -0,0 +1,28 @@
+/*
+ * 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.
+ *
+ */
+
+package org.onosproject.ui.table.cell;
+
+/**
+ * Formats integer values as hex strings.
+ */
+public class HexFormatter extends AbstractCellFormatter {
+    @Override
+    protected String nonNullFormat(Object value) {
+        return "0x" + Integer.toHexString((Integer) value);
+    }
+}