[giac] fix for floor on complexes, gettext-ization for step by step, sound functions

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@37617 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
fix for #4616 NPE

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@37618 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Changing giac.js to the latest version in web/kickstart.xml

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@37619 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e