[Kst] [Bug 126758] Set plot range as function of ctime

[Brisset, Nicolas]

> Also, I am now running with a mix of 'count nb of samples 
> from end' and the x-axis range expression, and there seems to 
> be an auto scaling bug in one of the barcharts.  It looks 
> like height is determined over more data than is plotted. 
That reminds me of something... Indeed, the default is to compute Y
autosale ranges for the whole data available (so that the ranges don't
jump continuously when scrolling through data), but I asked some time
ago for a "local Y" zoom mode, and it has been implemented. Maybe you
could use that to adjust the Y range "better" ?