Added last 2 units, added sidebar actions and build queue components, entities can now have their build actions put on the sidebar

lib/components/build_queue.rb

@@ -0,0 +1,14 @@
+class IMICRTS
+  class BuildQueue < Component
+    Item = Struct.new(:entity, :progress)
+    def initialize(parent:)
+      @parent = parent
+
+      @queue = []
+    end
+
+    def add(type)
+      @queue << Item.new(Entity.get(type), 0.0)
+    end
+  end
+end