[liblangtag/f20] (7 commits) ...enable unit tests

[David Tardon]

Summary of changes:

  512cf84... update build deps to current Packaging Guidelines (*)
  55933a4... drop extra vertical space (*)
  29a3d04... new upstream release 0.5.3 (*)
  9fbb78d... update subtag registry (*)
  e33d988... enable introspection (*)
  e372382... set verbose make rules at configure time already (*)
  1bd1808... enable unit tests (*)

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