Build HTTP queries specifically with '&'

[paazmaya]

http_build_query($requestParameters, null, '&');
instead of
http_build_query($requestParameters);

By default http_build_query uses php.ini value arg_separator.output which in most cases is & in order to make HTML valid, thus failing the request.

http://php.net/manual/en/function.http-build-query.php

[matthiasnoback]

Seems like a good suggestion. This problem was not reported before, but I think it makes sense.