Demo programs using Fl::args() and fl_get_system_colors() instead of
Fl_Window::show(argc,argv) didn't correctly initialize the Fl::scheme()
if the environment variable FLTK_SCHEME was set.
Calling Fl::scheme(Fl::scheme()) fixes this, because (currently) only
Fl::scheme(NULL) reads the environment variable FLTK_SCHEME.
git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@10565 ea41ed52-d2ee-0310-a9c1-e6b18d33e121
