set multiplot layout ... downwards|upwards

[Petr M. <mi...@ph...>]

I'm about to add two new keywords as the subject indicates:

       set multiplot { layout <cols>,<rows>
                       {rowmajor|columnmajor} {downwards|upwards}
			...

that specify vertical stacking of plot rows. The current, and default, is
downwards. I think the names are quite reasonable.

Further, I propose that if "set multiplot layout" is used, then "unset
multiplot" resets "size" to 1,1 and "origin" to 0,0. Otherwise, the next
plot is outside of the drawing canvas, and you have to do "set size ...; set
origin ..." explicitly. These values are not affected for normal "set
multiplot" for compatibility reasons. Any objections?

---
PM