new and improved non-integer figure handles * waitbar.m: Pass NaN and "integerhandle" property to __go_figure__. * __init_fltk__.cc (OpenGL_fltk::renumber, plot_window::renumber, figure_manager::renumber_figure, figure_manager::do_renumber_figure): New functions. (figure_manager::hnd2idx): Don't declare double arg as const. Include figure number in error message. (fltk_graphics_toolkit::update): Handle ID_INTEGERHANDLE. * graphics.h.in, graphics.cc (gh_manager::do_get_handle): Rename from gh_manager::get_handle. (gh_manager::get_handle): New static function. (gh_manager::renumber_figure): New static function. (gh_manager::do_renumber_figure): New function. (figure::properties::set_integerhandle): New function. (figure::properties::integerhandle): Tag property declaration with S. (F__go_figure__): Intercept and handle integerhandle property here. * graphics.h.in (children_property::renumber): New function. (base_properties::init_integerhandle): New virtual function. (figure::properties::init_integerhandle): New function. (base_properties::renumber_child, base_properties::renumber_parent): New functions.