{* *! version 1.0.0  12may2011}{...}
    {cmd:dofw(}{it:e_w}{cmd:)}
{p2colset 8 22 26 2}{...}
{p2col: Domain {it:e_w}:}{cmd:%tw} dates 0100w1 to 9999w52
           (integers -96,720 to 418,079){p_end}
{p2col: Range:}{cmd:%td} dates 01jan0100 to 24dec9999
           (integers -679,350 to 2,936,542){p_end}
{p2col: Description:}returns the {it:e_d} date (days since 01jan1960) of
           the start of week {it:e_w}.{p_end}
{p2colreset}{...}
