[Rd] header containing 8713 (PR#8729)

[j.van_den_hoff at fz-rossendorf.de]

concerning the symbols manpage:


it probably should actually say

"If 'inches' is 'FALSE', the units for the width and height of the 
symbols are taken to be those of the x axis and y axis, respectively..." 
at least for 'boxplots' symbols this is empirically the actual 
behaviour. if other symbols (e.g. circles) actually _are_ using x axis 
units, the difference between 'isotropic' and 'anisotropic' symobls 
should be made clear.

the current text gave me the false impression that I needed to set asp=1 
in order to get correct heights for the boxplots symbols.

joerg