Session management system

- Managers bound to the session instead of to Torch
- TorchSession automatic creation and destruction
- Automatic manager creation for sessions

Torch.API/Session/ITorchSessionManager.cs

@@ -0,0 +1,46 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Torch.API.Managers;
+
+namespace Torch.API.Session
+{
+    /// <summary>
+    /// Creates a manager for the given session if applicable.
+    /// </summary>
+    /// <remarks>
+    /// This is for creating managers that will live inside the session, not the manager that controls sesssions.
+    /// </remarks>
+    /// <param name="session">The session to construct a bound manager for</param>
+    /// <returns>The manager that will live in the session, or null if none.</returns>
+    public delegate IManager SessionManagerFactory(ITorchSession session);
+
+    /// <summary>
+    /// Manages the creation and destruction of <see cref="ITorchSession"/> instances for each <see cref="Sandbox.Game.World.MySession"/> created by Space Engineers.
+    /// </summary>
+    public interface ITorchSessionManager : IManager
+    {
+        /// <summary>
+        /// The currently running session
+        /// </summary>
+        ITorchSession CurrentSession { get; }
+
+        /// <summary>
+        /// Adds the given factory as a supplier for session based managers
+        /// </summary>
+        /// <param name="factory">Session based manager supplier</param>
+        /// <returns>true if added, false if already present</returns>
+        /// <exception cref="ArgumentNullException">If the factory is null</exception>
+        bool AddFactory(SessionManagerFactory factory);
+
+        /// <summary>
+        /// Remove the given factory from the suppliers for session based managers
+        /// </summary>
+        /// <param name="factory">Session based manager supplier</param>
+        /// <returns>true if removed, false if not present</returns>
+        /// <exception cref="ArgumentNullException">If the factory is null</exception>
+        bool RemoveFactory(SessionManagerFactory factory);
+    }
+}