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/erm/VR.lua

@@ -0,0 +1,22 @@
+local ReceiverBase = require("core:erm.ReceiverBase")
+
+local VR = ReceiverBase:new()
+
+function VR:new(ERM, v)
+	assert(v ~= nil, "!!VR requires variable identifier")
+	return ReceiverBase.new(self, {v=v, ERM=ERM})
+end
+
+local match = string.match
+
+local function trim(s)
+   return match(s,'^()%s*$') and '' or match(s,'^%s*(.*%S)')
+end
+
+function VR:H(flagIndex)
+	local v = trim(self.v)
+	self.ERM.F[flagIndex] = v ~= ''
+end
+
+
+return VR