Moved DecisionEngine to root of core.

NzbDrone.Core/DecisionEngine/RetentionSpecification.cs

@@ -0,0 +1,35 @@
+using System.Linq;
+using NLog;
+using NzbDrone.Core.Model;
+using NzbDrone.Core.Providers.Core;
+
+namespace NzbDrone.Core.DecisionEngine
+{
+    public class RetentionSpecification
+    {
+        private readonly ConfigProvider _configProvider;
+        private static readonly Logger logger = LogManager.GetCurrentClassLogger();
+
+        public RetentionSpecification(ConfigProvider configProvider)
+        {
+            _configProvider = configProvider;
+        }
+
+        public RetentionSpecification()
+        {
+            
+        }
+
+        public virtual bool IsSatisfiedBy(EpisodeParseResult subject)
+        {
+            logger.Trace("Checking if report meets retention requirements. {0}", subject.Age);
+            if (_configProvider.Retention > 0 && subject.Age > _configProvider.Retention)
+            {
+                logger.Trace("Report age: {0} rejected by user's retention limit", subject.Age);
+                return false;
+            }
+
+            return true;
+        }
+    }
+}