[vala/staging] (8 commits) ...vala: Allow get_actual_type() to be used for expected failures

[Rico Tzschichholz <ricotz src gnome org>]

Summary of changes:

  1ced9ce... vala: Add GenericType.get_actual_type() (*)
  d9c150c... vala: Add Method.compatible_no_error() (*)
  37573c3... vala: Don't just guess and check for a matching base_interf (*)
  3d1c706... vala: Search in all interfaces for an implementation match  (*)
  7516906... codegen: Do a proper check before connecting inherited impl (*)
  bad5965... vala: Collect implicit interface implementations (*)
  dd72593... vala: Allow explicit interface methods to be virtual (*)
  df3cee5... vala: Allow get_actual_type() to be used for expected failu (*)

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