Related: #i125293# More unified (still simple) CssStyles and solvers

(cherry picked from commit b760428400bbc7ab3db4d5de6239589e79981a06)

Conflicts:
	svgio/inc/svgio/svgreader/svgdocument.hxx
	svgio/inc/svgio/svgreader/svgnode.hxx
	svgio/inc/svgio/svgreader/svgstylenode.hxx
	svgio/source/svgreader/svgdocument.cxx
	svgio/source/svgreader/svgnode.cxx
	svgio/source/svgreader/svgstylenode.cxx

Change-Id: Ifcfc665df18f56e2cbc359411b633271c3b8d4bb