2.68.2 (stable):

Glib:
* Replace all g_quark_from_static_string() by g_quark_from_string()
  (Kjell Ahlstedt) Issue #96 (小太)

Gio:
* FileEnumerator: Remove refreturn to avoid memory leak
  (talisein) Merge request !53
* ListModel::get_object(): Make it work for interface classes
  (Kjell Ahlstedt) Issue #93 (pumkinpal)
* AppInfo::get_all(): Avoid a crash on Windows
  (Kjell Ahlstedt) Issue #94 (Lawrence37)

Build:
* MSVC build: Remove extraneous GLIBMM_API in Glib::ustring
  (Kjell Ahlstedt) Issue #92 (Christoph Reiter)