added comments in fl_draw.H, fl_color.cxx and fl_rect.cxx so that the links within drawing.dox can be simplified to allow LaTeX/PDF docs too. git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@6392 ea41ed52-d2ee-0310-a9c1-e6b18d33e121