Log Message:
Update to 0.16:

0.16
 * Clarify documentation for secret_service_clear_xxx() [#705629]
 * Pass return_type to prompt async begin functions, rather than finish
 * Simpler way to use custom service/collection/item types
 * service: Rename secret_service_new() and friends to xxx_open()
 * Add secret_value_get_text() function to return NULL terminated secret
 * Fix return types in secret_service_search_finish() on error paths [#698040]
 * Testing fixes [#705202]
 * Build fixes [#704233]
 * Updated translations