Added a basic custom editor for SpeechInputHandler

Author: aalmada

Assets/HoloToolkit/Input/Scripts/Voice/Editor/SpeechInputHandlerEditor.cs

@@ -0,0 +1,25 @@
+using System;
+using UnityEditor;
+using UnityEngine;
+
+namespace HoloToolkit.Unity.InputModule
+{
+    [CustomEditor(typeof(SpeechInputHandler))]
+    public class SpeechInputHandlerEditor : Editor
+    {
+        public override void OnInspectorGUI()
+        {
+            SerializedProperty keywordsAndResponses = serializedObject.FindProperty("KeywordsAndResponses");
+
+            serializedObject.Update();
+            EditorGUILayout.PropertyField(keywordsAndResponses, true);
+            serializedObject.ApplyModifiedProperties();
+
+            // error and warning messages
+            if (keywordsAndResponses.arraySize == 0)
+            {
+                EditorGUILayout.HelpBox("No keywords have been assigned!", MessageType.Warning);
+            }
+        }
+    }
+}