[NTG-context] floats disturb grid setting

[Max Chernoff]

Hi Hraban,

> > As soon as I use floats, text isn’t typeset on the grid any more:
> > 
> > 
> > \setuppaper[A5]
> > \setuplayout[grid=yes]
> > \showframe\showgrid
> 
> Oops, my bad: It must be "grid=on".
> But didn’t work "yes" in earlier versions?

I just tested:

             MkIV      MkXL
[grid=yes]   Broken    Broken
 [grid=on]   Broken    Works

-- Max