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.

scripts/lib/Metatype.lua

@@ -0,0 +1,24 @@
+local T =
+{
+	ARTIFACT = 1,
+	ARTIFACT_INSTANCE = 2,
+	CREATURE = 3,
+	CREATURE_INSTANCE = 4,
+	FACTION = 5,
+	HERO_CLASS = 6,
+	HERO_TYPE = 7,
+	HERO_INSTANCE = 8,
+	MAP_OBJECT_GROUP = 9,
+	MAP_OBJECT_TYPE = 10,
+	MAP_OBJECT_INSTANCE = 11,
+	SKILL = 12,
+	SPELL =	13
+}
+
+local M = setmetatable({},
+{
+	__newindex = function() error("Metatype table is immutable") end,
+	__index = T
+})
+
+return M