[giac] Implementing LocusEquation (part 2, works well in Chrome)

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@24959 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Conic section between limited quadric (cone/cylinder) and plane : part 2 (drawing in 2D view, parabola label)

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@24960 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e