Add Director, director::CommandList, hk::Goal and fixups

* Simulator and Director are no longer singletons.

hcore/include/director/director.h

@@ -0,0 +1,14 @@
+#ifndef DIRECTOR_H
+#define DIRECTOR_H
+
+namespace director {
+
+class Director {
+public:
+    Director() = default;
+    ~Director() = default;
+};
+
+} // namespace director
+
+#endif // DIRECTOR_H