libsecret is a library for storing and retrieving passwords and other 
secrets.  It communicates with the "Secret Service" using DBus.  Both
gnome-keyring and ksecretservice are implementations of a Secret Service.

libsecret (eventually) replaces libgnome-keyring.  Modules still using 
libgnome-keyring can coexist with others that have already been migrated 
to libsecret.
