[giac] upper_incomplete_gamma and polygamma added

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@24585 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
[giac] fix param. order for solveode

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@24586 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Pulled up setXML method

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@24587 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e