Allow running Web3D in IE offline

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@36953 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Make sure background image is updated on corner move

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@36954 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e