Fix nested array decoding
Fix nested array decoding

jQuery.map() is fundamentally broken. Don't use it.

According to the docs and actual practice, returning `null` removes that
entry from the resulting array, and returning an array concats that
array on to the result. Decoding nested arrays or arrays with `<nil>`s
would then result in stupid errors.

timheap/jquery-xmlrpc,timheap/xmlrpc.js,timheap/xmlrpc.js,timheap/jquery-xmlrpc,timheap/xmlrpc.js