Functions for importing external vector images and
drawing them as part of 'R' plots. This package is different from the
'grImport' package because, where that package imports 'PostScript'
format images, this package imports 'SVG' format images. Furthermore,
this package imports a specific subset of 'SVG', so external images
must be preprocessed using a package like 'rsvg' to produce 'SVG'
that this package can import. 'SVG' features that are not supported
by 'R' graphics, e.g., gradient fills, can be imported and then
exported via the 'gridSVG' package.