Added export to CSV in Kibana 3

I added a simple export.php file that leverages the elasticsearch scrolling id functions. It allows any widget to export to csv by calling the export.php with the ES query that was run for that particular widget. My hope is that it can be added and simply disabled if the user has no support for php. I've added the export button to the inspect window for all widgets, as I wanted to leverage the already generated curl statement information. Also base64'd the calls to ensure they worked in the php curl statement that does the scrolling.