Serializing and Deserializing RRuleSet yields different RRuleSet

[Dav1dde]

The Display impl of RRuleSet only serializes the contained rrule's not any of the other information:

rust-rrule/rrule/src/core/rruleset.rs

Lines 261 to 275 in 8da601c

	impl Display for RRuleSet {
	/// Prints a valid set of iCalendar properties which can be used to create a new [`RRuleSet`] later.
	/// You may use the generated string to create a new iCalendar component, like VEVENT.
	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
	let properties = self
	.rrule
	.iter()
	.map(ToString::to_string)
	.collect::<Vec<_>>()
	.join("\n");
	let datetime = datetime_to_ical_format(&self.dt_start);
	write!(f, "DTSTART{}\n{}", datetime, properties)
	}
	}

I would expect the following code to yield the same RRuleSet:

rrule_set.to_string().parse::<rrule::RRuleSet>().unwrap()

[fmeringdal]

Thanks for reporting. I will add a fix once time allows, unless someone else picks it up before then

[fmeringdal]

Proposed fix in #100 if you want to try it out before next release. It isn't a complete fix, but should hopefully cover most cases.