Fix for issue #65 - JotPad with &

Because the JS is calling the URL as a POST request, any **&** character in the data is being interpreted by the receiving **$_REQUEST** as a different field. Therefore, the data is truncated when it hits **json_decode** in **includes/JSON.php** and the function returns an error. Because it is an error code being returned by **json_decode**, the JotPad has nothing to save, therefore the data 'disappears'.

The solution is to URL encode the data far up in the execution path, so that the **&** is encoded before it becomes part of the POST data,