Water Content and Buildup of Poly(diallyldimethylammonium chloride)/Poly(sodium 4-styrenesulfonate) and Poly(allylamine hydrochloride)/Poly(sodium 4-styrenesulfonate) Polyelectrolyte Multilayers Studied by an in Situ Combination of a Quartz Crystal Microbalance with Dissipation Monitoring and Spectroscopic Ellipsometry