[libsecret] (10 commits) ...Merge branch 'wip/dueno/simple-item' into 'master'

[Daiki Ueno <dueno src gnome org>]

Summary of changes:

  938640a... secret-retrievable: New interface to represent read-only it (*)
  092d4ef... secret-item: Implement SecretRetrievableInterface (*)
  5fedca8... secret-password: Add search functions (*)
  bac85c0... secret-password: Add lookup_binary functions (*)
  29c1460... secret-password: Add store_binary functions (*)
  2ae6ec8... tests: Add tests for binary variant of secret_{lookup,store (*)
  a5db34d... secret-value: Add secret_value_unref_to_password (*)
  e3963ef... secret-password: Mark @schema argument nullable for *v func (*)
  6886aeb... secret-tool: Switch to using the simple API (*)
  f7e73ba... Merge branch 'wip/dueno/simple-item' into 'master'

(*) This commit already existed in another branch; no separate mail sent