Several nav tags are used without aria-label

Citing H97: Grouping related links using the nav element: "When the nav element is employed more than once on a page, distinguish the navigation groups by using an aria-label or aria-labelledby attribute.". The reason for this is that it allows screen reader users to more easily locate the right navigation or skip it. The Flamingo skin uses a <nav>-element for the top bar and another one for the drawer and should thus use an aria-label to label them. Note that Live Data uses another <nav>-tag for the pagination which should be labelled, too.