2.39.92 (unstable):

Gio:
* Application: Add add_main_option_entry() and add_option_group().
 (Murray Cumming)

Documentation:
* Glib::ustring: Say more clearly that it must be only UTF-8.
 (Kjell Ahlstedt) Bug #681560 (vurentjie)

Build:
* win32: Surround content_type_get_symbolic_icon() with ifdefs.
 (Giuseppe Penone)