[manual] suggested addition to pcolor description

[John W. Eaton]

On 23-Sep-2008, Francesco Potorti` wrote:

| >However, in Matlab there clearly is (as the color interpolates across  
| >each patch). Each rectangle of the mesh is interpreted as a pair of  
| >triangles and the color is linearly interpolated across it.
| 
| I see.  Thank you.  Probably this explanation should go into the
| documentation for `shading'.

If it has not happened already, could someone please propose a
changeset for this?

| Maybe with a note saying that the gnuplot backend does not implement
| "interp".

I think "interp" will work with gnuplot 4.3.  Can someone confirm?

Thanks,

jwe