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.

scripting/lua/api/battle/UnitProxy.cpp

@@ -0,0 +1,63 @@
+/*
+ * UnitProxy.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 "UnitProxy.h"
+
+#include "../../LuaStack.h"
+#include "../../LuaCallWrapper.h"
+#include "../Registry.h"
+
+namespace scripting
+{
+namespace api
+{
+namespace battle
+{
+
+VCMI_REGISTER_SCRIPT_API(UnitProxy, "battle.Unit")
+
+const std::vector<UnitProxy::RegType> UnitProxy::REGISTER =
+{
+	{
+		"getMinDamage",
+		LuaCallWrapper<const IBonusBearer>::createFunctor(&IBonusBearer::getMinDamage)
+	},
+	{
+		"getMaxDamage",
+		LuaCallWrapper<const IBonusBearer>::createFunctor(&IBonusBearer::getMaxDamage)
+	},
+	{
+		"getAttack",
+		LuaCallWrapper<const IBonusBearer>::createFunctor(&IBonusBearer::getAttack)
+	},
+	{
+		"getDefense",
+		LuaCallWrapper<const IBonusBearer>::createFunctor(&IBonusBearer::getDefense)
+	},
+	{
+		"isAlive",
+		LuaCallWrapper<const Unit>::createFunctor(&Unit::alive)
+	},
+	{
+		"unitId",
+		LuaCallWrapper<const IUnitInfo>::createFunctor(&IUnitInfo::unitId)
+	}
+};
+
+const std::vector<UnitProxy::CustomRegType> UnitProxy::REGISTER_CUSTOM =
+{
+
+};
+
+}
+}
+}