* Make sure this property is kept in sync so it can be used
immediately in the logic to retrieve secrets or other stuff.
* We don't wait for a PropertiesChanged, which may come later
* The SecretService methods aren't used as frequently as the
password methods, and it's not really necessary to have a whole
bunch of extra varargs functions.
* Add varargs functions for building a GHashTable of attributes
* Handled entirely on the client side.
* Schema names are stored in an xdg:schema attribute
* Add option to turn of matching on schema names. So that we can
lookup items stored by libgnome-keyring and others
* Change schema 'identifier' to 'name'
* Fix up tests
* Schemas can also be created dynamically
* Correct introspection types for hash tables passed as args
* Validate argument hash tables
* Add some predefined schemas
* Allow allocation of pageable passwords from lookup functions