[giac]: fix some commands.

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@24421 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
[giac] with multi-precision floats

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@24422 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e