Added tests for inkscape and sodipodi namespace declarations and attributes

unittests/inkscape.svg

@@ -1,5 +1,6 @@
 <svg xmlns="http://www.w3.org/2000/svg" xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
+xmlns:foo="http://www.inkscape.org/namespaces/inkscape"
 	inkscape:version="0.46" version="1.0">
 <inkscape:perspective inkscape:vp_x="0 : 526.18109 : 1" inkscape:vp_y="0 : 1000 : 0" inkscape:vp_z="744.09448 : 526.18109 : 1" inkscape:persp3d-origin="372.04724 : 350.78739 : 1" id="perspective3104"/>
-<rect width="300" height="200" fill="green" inkscape:collect="always"/>
+<rect width="300" height="200" fill="green" inkscape:collect="always" foo:bar="1"/>
 </svg>

unittests/sodipodi.svg

@@ -1,5 +1,6 @@
-<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd" sodipodi:version="0.32">
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
+xmlns:foo="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd" sodipodi:version="0.32">
   <sodipodi:namedview id="base" pagecolor="#ffffff" bordercolor="#666666" borderopacity="1.0" gridtolerance="10000" guidetolerance="10" objecttolerance="10"/>
-  <rect width="300" height="200" fill="green" />
+  <rect width="300" height="200" fill="green" sodipodi:bar="1" foo:baz="1"/>
 </svg>