Filezoo startup profile

Timed the startup of Filezoo. First, 200 ms of mono overhead (version 1.2.6), then 100 ms of pre-draw init (30 ms Gtk init, 60 ms Filezoo instance creation, 16 ms from Application.Run() to expose handler firing), 200 ms drawing the toolbar for the first time (i.e. loading fonts), and 100 ms for drawing the first frame, for a total of 600 ms. Slow. The ls program takes less than 50 ms.

I'm most shocked by mono's startup cost being so huge. A Hello World takes 100 ms to run in mono, whereas in a compiled language (tested with OCaml) it takes 1 ms.