2.12.8:

* Builder: get_widget(), get_widget_derived(): Correct a reference-counting 
  problem. (Murray Cumming)
* FileChooser: get_preview_widget(): Avoid an endless loop.
  Bug #543288 (Jens Georg)
* Printer::enumerate_printers(): Fix a refcounting problem found by Tor Krill.
  (Armin Burgmeier)
* Build:
  - Fix the build with --disable-api-exceptions (in glibmm).
  (Daniel Elstner)
  
Maemo-specific API:
* TextBuffer: get/set_rich_text_format(), set_rich_text_format_all(), 
  get/set_can_paste_rich_text(): Remove these Maemo-specific methods which have 
  been superseded by the generic TextBuffer serialization functions.
  (Daniel Elstner, Openismus)
* Enums
  - Added Maemo-specific Gtk::HildonSizeType, wrapping HildonSizeType, 
  which was inexplicably added to GTK+ in Maemo 5.
  - Likewise added Gtk::Hildon::InputMode, wrapping HildonGtkInputMode.
  (Daniel Elstner, Openismus)