For #4366
* u and v have symetrical behaviour for complex multiplication
* if we change u and v from complex to cartesian, u*v changes from complex number to number
* keep selected geos after store undo info

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@34612 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e