Change: Limit memory allocations for each Squirrel instance

This can avoid out-of-memory situations due to single scripts using up the entire address space.
Instead, scripts that go above the maximum are killed.
The maximum is default 1 GB per script, but can be configured by a setting.

src/ai/ai_instance.cpp

@@ -230,6 +230,7 @@ void AIInstance::Died()
 
 void AIInstance::LoadDummyScript()
 {
+	ScriptAllocatorScope alloc_scope(this->engine);
 	extern void Script_CreateDummy(HSQUIRRELVM vm, StringID string, const char *type);
 	Script_CreateDummy(this->engine->GetVM(), STR_ERROR_AI_NO_AI_FOUND, "AI");
 }

src/ai/ai_scanner.cpp

@@ -31,6 +31,8 @@ void AIScannerInfo::Initialize()
 {
 	ScriptScanner::Initialize("AIScanner");
 
+	ScriptAllocatorScope alloc_scope(this->engine);
+
 	/* Create the dummy AI */
 	free(this->main_script);
 	this->main_script = stredup("%_dummy");