Construction System. (#87)

* Construction WiP

* Construction kinda works!

* Lots more construction work.

* It mostly works!

Content.Shared/GameObjects/Components/Construction/SharedConstructorComponent.cs

@@ -0,0 +1,63 @@
+using System;
+using SS14.Shared.GameObjects;
+using SS14.Shared.Map;
+using SS14.Shared.Maths;
+using SS14.Shared.Serialization;
+
+namespace Content.Shared.GameObjects.Components.Construction
+{
+    /// <summary>
+    ///     Basically handles the logic of "this mob can do construction".
+    /// </summary>
+    public abstract class SharedConstructorComponent : Component
+    {
+        public override string Name => "Constructor";
+        public override uint? NetID => ContentNetIDs.CONSTRUCTOR;
+
+        /// <summary>
+        ///     Sent client -> server to to tell the server that we started building
+        ///     a structure-construction.
+        /// </summary>
+        [Serializable, NetSerializable]
+        protected class TryStartStructureConstructionMessage : ComponentMessage
+        {
+            /// <summary>
+            ///     Position to start building.
+            /// </summary>
+            public readonly GridLocalCoordinates Location;
+
+            /// <summary>
+            ///     The construction prototype to start building.
+            /// </summary>
+            public readonly string PrototypeName;
+
+            public readonly Angle Angle;
+
+            /// <summary>
+            ///     Identifier to be sent back in the acknowledgement so that the client can clean up its ghost.
+            /// </summary>
+            public readonly int Ack;
+
+            public TryStartStructureConstructionMessage(GridLocalCoordinates loc, string prototypeName, Angle angle, int ack)
+            {
+                Directed = true;
+                Location = loc;
+                PrototypeName = prototypeName;
+                Angle = angle;
+                Ack = ack;
+            }
+        }
+
+        [Serializable, NetSerializable]
+        protected class AckStructureConstructionMessage : ComponentMessage
+        {
+            public readonly int Ack;
+
+            public AckStructureConstructionMessage(int ack)
+            {
+                Directed = true;
+                Ack = ack;
+            }
+        }
+    }
+}