[giac] Fix for emscripten incompatibility compiling GMP on mpz_gcdext/invert

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@25391 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
[giac] serialize a⊗b as cross(a,b) rather than a⊗b

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@25392 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@25393 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
[giac] serialize a⊗b as cross(a,b) rather than a⊗b

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@25394 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
[giac] fix ToPolar

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@25395 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Attempt to fix preview image location

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@25396 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e