Rewrite display of decoplan: * Common stuff - fix clearing bottom of list, for fleecker-free updates. - fix "Wait..." topline_box while computing deco in planning - fix 'No Deco" std color and mark last page. - Allow stops up to 240' * ZHL-16c model: - 6 lines max (sim or dive) - Print exceed stops as "add: ddd'" * GF model - 6 lines in divemode, 8 in planning. - any suitable number of pages. - "more..." when not the last page displayed. - fix displaying special depth for last stop (CF#29). - fix 0-time stops: just skip display. - fix end of list when reached the deepest stop. - fix no need to buffer decoplan twice.