xml2json.php should not include a semi-colon at the end

[jng]

The switch to using JSON.parse over eval breaks on content returned by XML2JSON.php because it inserts a semi-colon at the end of the JSON literal (presumably to be eval()'d client-side). Since we don't eval() such content anymore (except for browsers that don't support a native JSON object), we should not be appending this semi-colon anymore.

To preserve existing behaviour for browsers where eval() is still used, it should check if the JSON string ends with a semi-colon, and append one if required before eval()-ing the string. Still this is a stop-gap measure until a JSON.parse() replacement is found for these browsers.