#3917 ImageCornersModel and applied to destktop.

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@30730 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Fix for #3923 ([web] navigation bar not showing)

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@30731 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e