Save base64 instead of XML

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@26626 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
[giac] changes for point() as argument of desolve, regressions, covariance/correlation, cross, *

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@26627 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Update GUI on file save

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@26628 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Close Dialogs with Back-button (Android)

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@26629 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@26630 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e