BASH pizza timer

Starts a countdown for the specified duration and displays a status bar along
the way. Duration is given similar to `sleep' arguments, e.g., 5m 30s.

Features:
    * Counting down progress bar (see below)
    * Alerts you via libnotify when finished

Example call:

$ timer 5m
Due: So 16. Jan 12:38:18 CET 2011
     284 [#############################################################....]