Recursive dependency trees

- Now TorchBase and TorchSession can each have seperate managers
- Managers now have a Dispose function that's run on shutdown

Torch.API/Managers/IManager.cs

@@ -12,8 +12,13 @@ namespace Torch.API.Managers
     public interface IManager
     {
         /// <summary>
-        /// Initializes the manager. Called after Torch is initialized.
+        /// Initializes the manager. Called once this manager's dependencies have been initialized.
         /// </summary>
         void Init();
+
+        /// <summary>
+        /// Disposes the manager.  Called before this manager's dependencies are disposed.
+        /// </summary>
+        void Dispose();
     }
 }