LIBZEITGEIST2 TODO:
 - Review examples: make sure they don't leak!
 - gtkdoc: document enum values
 - gtkdoc: make index.html nice
 - gtkdoc: add object hierarchy page
 - gtkdoc: split stuff (eg. datamodel.html) into 1 page for class
 - gtkdoc: fix api index so that eveyrthing isn't under Z
 - gtkdoc: show properties & signals!!
 - lots of documentation missing
 - make zeitgeist_events_to_variant_with_limit internal?
 - make utils.* internal?
 - "introduced result_type_is_sort_order_asc" - add to NEWS or hide it
