[ ] improve lel-open to support multiple files.
[ ] zooming
	[ ] improve performance (cull only the visible part?), use XGetImage() ?
	[ ] improve zoomfact "steps".
[ ] mouse support.
	[ ] mouse move panning.
	[x] mouse scroll zooming.
[ ] scale
	[ ] use XPutPixel for byte-order safety ?
[ ] improve README.
[ ] write man page.
	[ ] lel.1
	[ ] lel-open.1
[?] for pictures which use an alpha mask use a checked pattern, similar to:
    http://www.modejong.com/blog/Media/Ghost_TransparentBG_400x300.jpg
[?] improve key lookup code.
[?] project name change.
[?] add support for more color depths (< 24).
[?] add command mode or shell support for viewing
    images in a directory (output key to stdout might be enough?).
