`get_all_opt` now flattens the content of objects

`get_all_opt` now flattens the content of objects

So now in a configuration with multiple section with the same name, for
example:

	module {
		param1 = value1;
		param2 = value2;
	}
	module {
		param2 = value2_1;
		param3 = value3;
	}

this function will return a single lua table that looks as following:

	param1 = value1,
	param2 = value2_1,
	param3 = value3