Log Message:
Update ristretto to 0.8.2:

0.8.2
=====
- Implement sorting by file type (Bug #12749)
- Detect image type by its mime type instead of file extension
  (ligmagic is used) (Bugs #11680, 12499)
- Allow images to be flipped vertically and horizontally (Bug #13313)
- Fix memory leaks

* Translation updates:
  Catalan (ca), Czech (cs), Danish (da), Deutsch (de), English (Australia)
  (en_AU), Spanish (es), French (fr), Hebrew (he), Croatian (hr), Italian (it),
  Japanese (ja), Kazakh (kk), Korean (ko), Lithuanian (lt), Malay (ms),
  Norwegian Bokm?l (nb), Polish (pl), Portuguese (pt), Portuguese (Brazilian)
  (pt_BR), Russian (ru), Slovak (sk), Swedish (sv), Ukrainian (uk), Chinese
  (China) (zh_CN), Chinese (Taiwan) (zh_TW).

0.8.1
=====
- Prepare for gtk3 migration: Do not include individual headers;
  Replace GDK_<keyname> with GDK_KEY_<keyname>;
  Use gtk_widget_get_allocation; Use gtk_widget_get/set_window;
  Use gtk_widget_get/set_style; Do not use GTK_WIDGET_* macros;
  Use accessor functions instead of direct access;
  Do not use deprecated symbols; Do not use deprecated GTK_STOCK_*;
  Use cairo for drawing; Do not use GDK_DISPLAY()
- Check if file name is a valid utf8 string to avoid crashes (Bug #12445)
- Fix SEGFAULT when pressing Delete without shown image (Bug #12860)
- Fix memory leak in thumbnailer if image file not found (Bug #12034)
- Prevent from using garbage values when pixbuf==NULL
- Fix NULL pointer dereference
- Remove dead code; found by Coverity
- Fix possible NULL pointer dereference; found by Coverity
- Added option to "not ask again for this session" when sending files \ 
to the
  trash. Image deletions still require confirmation.
- Replaced "GTK_WIDGET(window)->window" with more future compatible
  "gtk_widget_get_window(GTK_WIDGET(window))"
- ESC-key now quits Ristretto, or pauses a running slideshow
- Remember last location in save-copy dialog
- Use default filename in save-copy dialog
- Disable save-copy dialog if no image is loaded
- Fix various memory leaks
- Appdata fails validation (Bug #11622)
- Fix icon installation (Bug #11614)

* Translation updates:
  Arabic (ar), Bulgarian (bg), Catalan (ca), Czech (cs), Danish (da),
  German (de), Greek (el), English (Australia) (en_AU), Spanish (es),
  French (fr), Hebrew (he), Hungarian (hu), Icelandic (is), Italian (it),
  Japanese (ja), Kazakh (kk), Korean (ko), Lithuanian (lt), Malay (ms),
  Norwegian Bokm?l (nb), Dutch (nl), Polish (pl), Portuguese (pt),
  Portuguese (Brazilian) (pt_BR), Romanian (ro), Russian (ru), Slovak (sk),
  Swedish (sv), Thai (th), Turkish (tr), Ukrainian (uk),
  Chinese (China) (zh_CN), Chinese (Taiwan) (zh_TW).