[vala] (9 commits) Created branch staging

[Rico Tzschichholz <ricotz src gnome org>]

The branch 'staging' was created.

Summary of new commits:

  9e9e5b5... glib-2.0: Drop g_object_unref which is part of gobject-2.0
  b62335f... tests: Add some minimal test cases to catch insufficient he
  4ec3949... vala: Add Delegate/Method/ObjectTypeSymbol.has_type_paramet
  3cb608f... vala: Use DataType.get_type_arguments()
  dc3d9b5... codegen: Add type declarations required for generics as nee
  df83b4f... codegen: Add type declaration for method errors and error d
  dea1e95... codegen: Add required headers for ctor/dtor of compact clas
  9573e80... codegen: Don't explicitly add glib headers, using symbols w
  d287360... codegen: Don't emit type_id for enum in non GOBJECT profile