version 3.9.1
 - Fix UI string in avatar chooser test
 - Use AM_VALAFLAGS rather than VALAFLAGS
 - Avoid Vala warning about copying delegates
   Mark the variable in which CountdownCallback is stored as unowned, as it
   is simply a pointer to the callback.
 - Use "autocluttersink" instead of "cluttersink"
 - Use clutter_actor_set_background_color
   Instead of the deprecated cltuter_stage_set_color, use
   clutter_actor_set_background_color.
 - Use clutter_actor_add_child
   Instead of using the deprecated clutter_container_add_actor, use
   clutter_actor_add_child.
 - Avoid deprecated clutter_actor_animate
   Use implicit animation instead.
 - Avoid deprecated clutter_table_layout_set_expand
   Use the "expand-x" and "expand-y" properties on ClutterActor instead
   (which are both set to false by default).
 - Use ClutterActor rather than ClutterRectangle
 - User ClutterActor rather than ClutterBox
   ClutterBox is deprecated.
 - Bump required versions of Clutter and GIO
   GIO 2.32 or above is required for GMenu support and Clutter 1.12 is
   required to make use of new API to avoid deprecation warnings when using
   Clutter 1.12 or above.
 - Avoid Vala compiler warning about implicit begin
 - Fix cheese_thumb_view_new() prototype
 - Remove some unnecessary "static" keywords
   This avoids some warnings from the Vala compiler.
 - Update burst mode help page
   Improve the wording, add more details about the preference dialog.
 - Update the gschema to use "photo" and "image"
   Use "photo" and "image" instead of "picture" so that the schema
   descriptions are more consistent and precise.
 - Improve "Fire Flash" string in the Preferences
   Change "Fire Flash" to "Fire flash" because it is not a title, so should
   not use header capitalisation.
 - Fix typos in help