notification improvements: play sound, basic system tray icon support
See issue #77 (closed) for further details.
This branch implements the following improvements/extensions:
(1) New messages sound
Balsa had an option for playing a sound when new messages arrive, which
was a no-op. Make this option functional, and unify playing sound
(requires libcanberra).
(2) Basic System Tray Icon support
Add an option to display a System Tray icon which
- changes the colour when new messages arrived,
- shows/hides the Balsa main window on primary click,
- shows a simple menu on secondary click. (requires libxapp, not supported by all desktop environments/wm's).
Signed-off-by: Albrecht Dreß albrecht.dress@netcologne.de
Closes #77 (closed)