Though byte[] types are treated as hex strings in
general it failed for byte[] in GenericArrayType. THis
failed for example class X { List<byte[]> x}. The results
was that byte[] types were encoded as javascript arrays.
So now we also make those hex strings.
Added url to data object
Fix #350: Do not print stacktrace during offline builds

Signed-off-by: Ferry Huberts <ferry.huberts@pelagic.nl>