Entities redesign and a few ERM features

* Made most Handlers derived from CHandlerBase and moved service API there.
* Declared existing Entity APIs.
* Added basic script context caching
* Started Lua script module
* Started Lua spell effect API
* Started script state persistence
* Started battle info callback binding
* CommitPackage removed
* Extracted spells::Caster to own header; Expanded Spell API.
* implemented !!MC:S, !!FU:E, !!FU:P, !!MA, !!VR:H, !!VR:C
* !!BU:C, !!BU:E, !!BU:G, !!BU:M implemented
* Allow use of "MC:S@varName@" to declare normal variable (technically v-variable with string key)
* Re-enabled VERM macros.
* !?GM0 added
* !?TM implemented
* Added !!MF:N
* Started !?OB, !!BM, !!HE, !!OW, !!UN
* Added basic support of w-variables
* Added support for ERM indirect variables
* Made !?FU regular trigger
* !!re (ERA loop receiver) implemented
* Fixed ERM receivers with zero args.

lib/events/TurnStarted.cpp

@@ -0,0 +1,39 @@
+/*
+ * TurnStarted.cpp, part of VCMI engine
+ *
+ * Authors: listed in file AUTHORS in main folder
+ *
+ * License: GNU General Public License v2.0 or later
+ * Full text of license available in license.txt file, in main folder
+ *
+ */
+#include "StdInc.h"
+
+#include "TurnStarted.h"
+
+#include <vcmi/events/EventBus.h>
+
+namespace events
+{
+
+SubscriptionRegistry<TurnStarted> * TurnStarted::getRegistry()
+{
+	static std::unique_ptr<SubscriptionRegistry<TurnStarted>> Instance = make_unique<SubscriptionRegistry<TurnStarted>>();
+	return Instance.get();
+}
+
+void TurnStarted::defaultExecute(const EventBus * bus)
+{
+	CTurnStarted event;
+	bus->executeEvent(event);
+}
+
+CTurnStarted::CTurnStarted() = default;
+
+bool CTurnStarted::isEnabled() const
+{
+	return true;
+}
+
+
+}