3.22.0: (stable)

* Add the "Building applications" chapter with example code.
  (Kjell Ahlstedt) Bug #772391
* Document that Gtk::Action and some other classes are deprecated.
  (Kjell Ahlstedt)
* Add the ListModel example.
  (Kjell Ahlstedt) Bug #755149
* gmmproc section: Document new options in _CLASS_GTKOBJECT.
  (Kjell Ahlstedt) Bug #767951
* Printing examples: Add missing menu items and toolbar.
  (Kjell Ahlstedt)
* Printing advanced example: Don't use deprecated methods.
  (Kjell Ahlstedt)
* gmmproc section: Describe the err_return_value argument in _WRAP_VFUNC.
  (Kjell Ahlstedt)
* Calendar example: Don't use deprecated font: CSS syntax.
  (Murray Cumming)
* Custom widget and calendar examples: Don't crash when showing errors.
  (Murray Cumming)
* gmmproc section: Document all options in _WRAP_ENUM and _WRAP_GERROR.
  (Kjell Ahlstedt)
* gmmproc section: Add description of _CUSTOM_MOVE_OPERATIONS macro.
  (Marcin Kolny)