3.18.0:

* Input example: Fix high CPU load, by opening the fifo in read/write mode.
  (Kjell Ahlstedt)
* command_line_handling example: handle_local_options(): Correct the return
  values, now that glib bug #750796 was fixed.
  (Murray Cumming) Bug #754763
* combobox/complex example: Show use of a cell_data_func().
  (Murray Cumming)
* examples: Remove unnecessary virtual keywords.
  (Murray Cumming)
* C++11: examples: Replace deprecated std::auto_ptr by std::unique_ptr.
  (Kjell Ahlstedt)
* C++11: examples: Use the override keyword.
  (Murray Cumming)
* gmmproc chapter:
  Document _CUSTOM_* gmmproc macros
  (Kjell Ahlstedt)