Fix for #3651

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@30541 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
#3808: make unit vector nicer using normal()

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@30542 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
start with the convex hull of a polygon3D

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@30543 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e