Fixed bugs with token '<' and [object Object]

https://github.com/Ruxton92/jqueryupload/commit/d213fc52e1e767c9fd9815220a26a43bba8ea452#diff-64a85363f76103f7a8596eaeed5e8e18L76
There was a trouble with .join: createInputs() returns [object Object], not array.
https://github.com/Ruxton92/jqueryupload/commit/d213fc52e1e767c9fd9815220a26a43bba8ea452#diff-64a85363f76103f7a8596eaeed5e8e18L118
$(contents).find('body').html() return response message wrapped with html, so it can't be parsed as JSON.