In addition to the obvious simplification to the code by removing all the
window creation stuff, this also allows us to let users pick whether they
want to run fookb as a dockapp or as a normal windowed application at
runtime using libdockapp's --windowed command line option. Previously,
this was done during build using configure's --enable-wmaker option.
Previously, we would try and read the width and height of images read from
an XPM file *before* doing any error handling to determine whether we
successfully read the file in the first place. If there had been an error,
then there would be a segfault.
