Moved Extension methods in common to subfolder

src/NzbDrone.Common/Extensions/DictionaryExtensions.cs

@@ -0,0 +1,32 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace NzbDrone.Common.Extensions
+{
+    public static class DictionaryExtensions
+    {
+        public static TValue GetValueOrDefault<TKey, TValue>(this IDictionary<TKey, TValue> dictionary, TKey key, TValue defaultValue = default(TValue))
+        {
+            TValue value;
+            return dictionary.TryGetValue(key, out value) ? value : defaultValue;
+        }
+
+        public static Dictionary<T1, T2> Merge<T1, T2>(this Dictionary<T1, T2> first, Dictionary<T1, T2> second)
+        {
+            if (first == null) throw new ArgumentNullException("first");
+            if (second == null) throw new ArgumentNullException("second");
+
+            var merged = new Dictionary<T1, T2>();
+            first.ToList().ForEach(kv => merged[kv.Key] = kv.Value);
+            second.ToList().ForEach(kv => merged[kv.Key] = kv.Value);
+
+            return merged;
+        }
+
+        public static void Add<TKey, TValue>(this ICollection<KeyValuePair<TKey, TValue>> collection, TKey key, TValue value)
+        {
+            collection.Add(key, value);
+        }
+    }
+}