If you have everything installed in the default directories, then you
can so this at a shell prompt:

   ./configure
   make

If you want to use the Fltk libs and includes out of the source archive, 
(useful if you don't have access to install Fltk), then you can use the
"with-fltk-dir" option:

  ./configure --with-fltk-dir=/path/to/fltk
  make

This will create the tree_demo and the *.o files for the Fl_ToggleTree.
