Added endpoint and functionality for getting, retrieving and deleting bookmarks, and for adding and removing tags for a bookmark

YABA.Common/Extensions/DictionaryExtensions.cs

@@ -0,0 +1,24 @@
+using System;
+using System.Collections.Generic;
+
+namespace YABA.Common.Extensions
+{
+    public static class DictionaryExtensions
+    {
+        public static void AddRange<K, V>(this Dictionary<K, V> source, Dictionary<K, V> collection)
+        {
+            if (collection == null)
+            {
+                throw new ArgumentNullException("Collection is null");
+            }
+
+            foreach (var item in collection)
+            {
+                if (!source.ContainsKey(item.Key))
+                {
+                    source.Add(item.Key, item.Value);
+                }
+            }
+        }
+    }
+}