cow-notify, fork from dwmstatus

Notification daemon that runs on background and executes configured script.

The script get as arguments the time of expiration of the notification, its summary and its content.

The script will be looked at $XDG_CONFIG_HOME/cow-notify/config, then, if none is found, at
$HOME/.config/cow-notify/config. If there is no script, the program will carry on but nothing
will be executed when receiving notifications.

Issues :
	* Fails to reply on some python programs (?)