add some "alarm" on !maemo

[gregoa]

it might be nice to have some reminders/notifications on debian without the maemo-specific libalarm (libnotify?)

[philipp]

We have several possibilities:

• Libnotify: Is not available on Windows (if you don't take ​http://code.google.com/p/libnotifywin/ into account)
• QSystemTrayIcon::showMessage: Without calling show we don't get a message in the awesome window manager. If we call show it works but (at least without icon) the notification is shown on an arbitrary location the first time. On Windows, we could have a phantom icon.
• QApplication::alert: Is not really a notification.

[gregoa]

mostly done in r1516 (with QSystemTrayIcon)

[gregoa]

fixed in r1517