
Using embedded pixmap data to display an image.
While I do like the convenience of an external directory for RGB images
(where you can quickly swap images when necessary), pixmaps are great for
small images that are often used as part of a user interface.
Embedding them in the script can make it much more portable.

my_widget:image(fltk:Fl_Pixmap(xpm_data))

xpm_data is a table containing the pixmap data.
Unlike an XPM file, which often contains C comments (/* comment */) and
requires that /* XPM */ be its first line, the image data that Fl_Pixmap
uses must be only the image data itself, each line being a table index.

The first line is a string of four integers representing the number of
columns, rows, colors, and characters per pixel, in that order.

The next series of lines are the color definitions.

Finally are the lines representing the visual layout of the image.
