GS: Charge 5000 opcodes to call ScriptTown::FoundTown

This call is very expensive and calling it in a loop when it fails
can consume all available CPU time

Add a further 50000 charge if a town name cannot be generated

src/script/api/script_controller.cpp

@@ -95,6 +95,11 @@ ScriptController::~ScriptController()
 	return ScriptObject::GetActiveInstance()->GetOpsTillSuspend();
 }
 
+/* static */ void ScriptController::DecreaseOps(int amount)
+{
+	Squirrel::DecreaseOps(ScriptObject::GetActiveInstance()->engine->GetVM(), amount);
+}
+
 /* static */ int ScriptController::GetSetting(const char *name)
 {
 	return ScriptObject::GetActiveInstance()->GetSetting(name);