Fix for Derivative[ sin(g(x)),3 ], simplified toString

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@35542 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
bugfix for freehandmode (web)

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@35543 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e