Needed for 1.0
--------------

 - check that all public but unstable API is properly guard off with
   I_KNOW_THIS_API_IS_SUBJECT_TO_CHANGE_ETC

 - man page review / section review

 - make sure library API is reasonably MT-safe

 - avoid watching all name owner changes in PolkitBackendAuthority and
   PolkitBackendServer; remove the name-owner-changed vfunc

GNOME Authentication Agent
--------------------------

 - maybe expand on the notification icon so it is more detailed
   what temporary authorizations the session has - and maybe a way
   to only drop some of them