Annotations: let user add unlimited meta annotations

If a user is presented the add-annotation-dialog, (s)he can now add multiple
meta annotations instead of only one. Every meta annotations refers to the
(meta) annotation above it (in the dialog) and one can therefore build a
hierarchy chain with this.
Annotations navigator: add tooltip for duplicate button
Annotations navigator: add re-root button

This button will remove all upstream nodes of the current path that are not
needed to get the current view.
Annotations navigator: add filter chain break dependent path delimiter