[giac] Fix implicit assumptions from sqrt argument to be valid only during normal. Improve some integral output like int(x/sin(x)^2)

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@25750 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@25751 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e