xfce4-notifyd: update to 0.6.4

Change log:

0.6.4
======
- settings: Improve app icon and name matching
- settings: Sort known apps by notification count
- settings: Show 'Unspecified app' instead of empty line
- daemon: Improve application icon matching
- Correctly reset position during slideout (Fixes #42)
- panel-plugin: Remove duplicate function call (Fixes #40)
- panel-plugin: Fix file monitor (Fixes #40)
- Properly free the GKeyFile
- tests: Add logging test
- Fix compiler warnings
- Fix tooltip grammar
- build: Fix intltool lock file problem during make distcheck
- Update gitignore
- Update COPYING (#61)
- Translation Updates:
  Albanian, Basque, Belarusian, Bulgarian, Catalan, Chinese (China),
  Chinese (Taiwan), Czech, Danish, Dutch, Eastern Armenian, Estonian,
  French, Galician, German, Greek, Hebrew, Indonesian, Italian,
  Japanese, Kazakh, Korean, Lithuanian, Malay, Norwegian Bokm奪l,
  Polish, Portuguese, Portuguese (Brazil), Russian, Serbian, Slovak,
  Slovenian, Spanish, Swedish, Thai, Turkish, Ukrainian

(gutteridge)