Multiple fixes from Sebastien.

CHANGES

FL/Fl.H

README

documentation/Fl_Tiled_Image.html

documentation/intro.html

src/Fl_Button.cxx

src/Fl_Chart.cxx

src/Fl_File_Chooser.cxx

src/Fl_File_Chooser.fl

src/Fl_GIF_Image.cxx

src/Fl_Gl_Window.cxx

src/Fl_Help_View.cxx

src/Fl_PNG_Image.cxx

src/Fl_PNM_Image.cxx

src/Fl_Shared_Image.cxx

src/Fl_Tiled_Image.cxx

src/Fl_XBM_Image.cxx

src/Fl_arg.cxx

src/filename_absolute.cxx

src/filename_expand.cxx