Add a chat system that actually looks nice.

mods/artifact_hud/init.lua

@@ -77,6 +77,11 @@ function ns.hud_add(m, def)
     if type.defaults then
         def = extend(table.copy(type.defaults), def)
     end
+    -- Create a random name if none is given, since the
+    -- assumption is that the user doesn't care about the name.
+    if not def.name then
+        def.name = ""..math.random()
+    end
     local el
     if m.hud[def.name] then
         el = m.hud[def.name]
@@ -222,8 +227,11 @@ ns.register_hud_type {
         end
     end,
     remove = function(e, m)
+        m.hud[e.name] = nil
         m.object:hud_remove(e._id)
         e._id = nil
+        -- Prevent ongoing animations from attempting to change a nonexistent element.
+        e.update = function() end
     end
 }
 
@@ -270,5 +278,7 @@ ns.register_hud_type {
         m.hud[e.name] = nil
         m.object:hud_remove(e._id)
         e._id = nil
+        -- Prevent ongoing animations from attempting to change a nonexistent element.
+        e.update = function() end
     end
 }