1.9.2:

* Removed SourceMarker because GtkSourceMarker was removed from the C API.
* SourceBuffer: Removed create_marker(), move_marker(), delete_marker(), 
  get_marker(), get_markers_in_region(), get_first_marker(), 
  get_last_marker(), get_iter_at_marker(), get_next_marker(), 
  and get_prev_marker(), because the C functions were removed 
  from the C API.
* SourceView: Remove set_marker_pixbuf(), get_marker_pixbuf(), 
  set_show_line_markers(), and get_show_line_markers(), 
  because the C functions were removed from the C API.