[giac] Add () for output of e^x to a power. Other CAS fixes

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@29233 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Removed warnings

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@29234 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@29235 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e