Urist's damage and health thing. (#10)

* Add prototype for temperature testing entity.

* Add Damageable, Destructible, Temperature. Add a prototype based on those.

* Works and cleaned up.

* Nerf

Content.Server/Interfaces/GameObjects/IOnDamageBehavior.cs

@@ -0,0 +1,27 @@
+using System.Collections.Generic;
+using Content.Server.GameObjects;
+
+namespace Content.Server.Interfaces
+{
+    /// <summary>
+    /// Any component/entity that has behaviour linked to taking damage should implement this interface.
+    /// TODO: Don't know how to work around this currently, but due to how events work
+    /// you need to hook it up to the DamageableComponent via Initialize().
+    /// See DestructibleComponent.Initialize() for an example.
+    /// </summary>
+    interface IOnDamageBehavior
+    {
+        /// <summary>
+        /// Gets a list of all DamageThresholds this component/entity are interested in.
+        /// </summary>
+        /// <returns>List of DamageThresholds to be added to DamageableComponent for watching.</returns>
+        List<DamageThreshold> GetAllDamageThresholds();
+
+        /// <summary>
+        /// Damage threshold passed event hookup.
+        /// </summary>
+        /// <param name="obj">Damageable component.</param>
+        /// <param name="e">Damage threshold and whether it's passed in one way or another.</param>
+        void OnDamageThresholdPassed(object obj, DamageThresholdPassedEventArgs e);
+    }
+}