[giac] incomplete gamma implemented

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@24539 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Pulled up more stuff from AppW to AppWeb

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@24540 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
[giac] Intersect, Zipf, ODE solving (2/3 args)

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@24541 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e