* Older versions of gnome-keyring erroneously set this content type
for passwords even though they're textual.
* If we see this content type, then check if the password is textual
and allow usage as a null-terminated password
* 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
