[giac] initializing Giac with caseval("init geogebra") (needed after r25186)

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@25214 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Preview test

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@25215 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Make sure that startAnimation is called for HTML5 applets #3265

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@25216 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e