CurrentSession available directly from TorchBase

SteamService is now properly injected for clients, and reports errors
Obsolete tags on the manager properties in TorchBase

Torch.API/ITorchBase.cs

@@ -4,6 +4,7 @@ using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 using Torch.API.Managers;
+using Torch.API.Session;
 using VRage.Game.ModAPI;
 
 namespace Torch.API
@@ -33,15 +34,22 @@ namespace Torch.API
         /// </summary>
         event Action SessionUnloaded;
 
+        /// <summary>
+        /// Gets the currently running session instance, or null if none exists.
+        /// </summary>
+        ITorchSession CurrentSession { get; }
+
         /// <summary>
         /// Configuration for the current instance.
         /// </summary>
         ITorchConfig Config { get; }
 
         /// <inheritdoc cref="IMultiplayerManager"/>
+        [Obsolete]
         IMultiplayerManager Multiplayer { get; }
 
         /// <inheritdoc cref="IPluginManager"/>
+        [Obsolete]
         IPluginManager Plugins { get; }
 
         /// <inheritdoc cref="IDependencyManager"/>