New: Check whether an existing episode file was deleted before grabbing an upgrade, to avoid timing issues in combination with Ignore Deleted Episodes.

src/NzbDrone.Core/DecisionEngine/SpecificationPriority.cs

@@ -0,0 +1,10 @@
+namespace NzbDrone.Core.DecisionEngine
+{
+    public enum SpecificationPriority
+    {
+        Default = 0,
+        Parsing = 0,
+        Database = 0,
+        Disk = 1
+    }
+}