getFrameElement() added to AppW; used for file DnD

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@29425 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
fix for web Perspective file save problem (needs testing) 

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@29426 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e