Quick Plot: Map image and legend should "fit in"

[jng]

Currently, depending on paper size and print element configuration, the final plotted PDF can look out of place. The reason for this is that the print size determines the size of the PDF, but the image requests assume this to be the same for the map and legend images to request, which is not true.

Instead, the plotting code should be smarter and render the print elements first (title, scalebar, disclaimer), and then adjust the print size as necessary to get a map and/or legend that fits nicely in the remaining PDF space

[jng]

Fixed r2767