missing implementation for com.sun.star.svg.SVGWriter when using
GraphicProvider

Adapted patch provided by Sven Jacobi (thanks), added some fixes/cleanups to
make it work with all kind of graphics (SVG, Bitmap, Metafile)

(cherry picked from commit 89101118)

Conflicts:
	filter/inc/filter/msfilter/msdffimp.hxx
	filter/source/graphicfilter/epict/epict.cxx
	filter/source/svg/svgexport.cxx
	filter/source/svg/svguno.cxx
	filter/source/svg/svgwriter.cxx
	filter/source/svg/svgwriter.hxx
	svtools/source/filter/filter.cxx

Change-Id: Ie53f995614060a00c709f620f89d132913a25c5c