Click Migration (#94)

* Migrated Interaction system to the new Input system.

* Contexts are now set up in content.

Content.Client/Input/ContentContexts.cs

@@ -0,0 +1,23 @@
+using Content.Shared.Input;
+using SS14.Shared.Input;
+
+namespace Content.Client.Input
+{
+    /// <summary>
+    ///     Contains a helper function for setting up all content 
+    ///     contexts, and modifying existing engine ones.
+    /// </summary>
+    public static class ContentContexts
+    {
+        public static void SetupContexts(IInputContextContainer contexts)
+        {
+            var human = contexts.GetContext("human");
+            human.AddFunction(ContentKeyFunctions.SwapHands);
+            human.AddFunction(ContentKeyFunctions.Drop);
+            human.AddFunction(ContentKeyFunctions.ActivateItemInHand);
+            human.AddFunction(ContentKeyFunctions.OpenCharacterMenu);
+            human.AddFunction(ContentKeyFunctions.ExamineEntity);
+            human.AddFunction(ContentKeyFunctions.UseItemInHand);
+        }
+    }
+}