[giac] make sure {1,2,3}^2 works again

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@25900 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Using algo to plot 3D curves :
* remove previous changes
* create new classes

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@25901 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e