Build up a hash table of attribute values.
The variable argument list should contain pairs of a) The attribute name as a null-terminated string, followed by b) attribute value,
either a character string, an int number, or a gboolean value, as defined in the password schema. The list of attributes
should be terminated with a null.
| schema |
the schema for the attributes |
| va |
the attribute keys and values, terminated with |
|
a new table of attributes, to be released with [func |