Healing component and Medkit (#143)

Medkit to heal yourself and your buddy
known issues:
- [ ] it doesn't restore screen effects that happens when health status go into crit and dead

Content.Server/GameObjects/Components/Healing/HealingComponent.cs

@@ -0,0 +1,64 @@
+using System;
+using SS14.Shared.GameObjects;
+using Content.Server.GameObjects.EntitySystems;
+using SS14.Shared.Interfaces.GameObjects;
+using SS14.Shared.Map;
+using SS14.Shared.IoC;
+using SS14.Server.GameObjects;
+using SS14.Shared.Maths;
+using SS14.Server.Interfaces.GameObjects;
+using SS14.Shared.Interfaces.Timing;
+using SS14.Shared.GameObjects.EntitySystemMessages;
+using SS14.Shared.Serialization;
+using SS14.Shared.Interfaces.GameObjects.Components;
+using Content.Shared.GameObjects;
+
+namespace Content.Server.GameObjects.Components.Weapon.Melee
+{
+    public class HealingComponent : Component, IAfterAttack, IUse
+    {
+        public override string Name => "Healing";
+
+        public int Heal = 100;
+
+        public override void ExposeData(ObjectSerializer serializer)
+        {
+            base.ExposeData(serializer);
+
+            serializer.DataField(ref Heal, "heal", 100);
+        }
+
+        void IAfterAttack.Afterattack(IEntity user, GridCoordinates clicklocation, IEntity attacked)
+        {
+            if (attacked == null)
+            {
+                return;
+            }
+            if (attacked.TryGetComponent(out DamageableComponent damagecomponent))
+            {
+                damagecomponent.TakeHealing(DamageType.Brute, Heal);
+                DropAndDelete(user);
+            }
+        }
+
+        bool IUse.UseEntity(IEntity user)
+        {
+            if (user.TryGetComponent(out DamageableComponent damagecomponent))
+            {
+                damagecomponent.TakeHealing(DamageType.Brute, Heal);
+                DropAndDelete(user);
+                return false;
+            }
+            return false;
+        }
+
+        void DropAndDelete(IEntity user)
+        {
+            if(user.TryGetComponent(out HandsComponent handscomponent))
+            {
+                handscomponent.Drop(Owner);
+                Owner.Delete();
+            }
+        }
+    }
+}