Develop ajax

Hey Ollie, 

We've done a large amount of work on getting effective feedback from the syncing process, so we built in AJAX requests to give good feedback on the process. 

We also worked with the issue with media upload for files of type other than image (for WordPress <3.4). 

We're continuing to work on WP 3.5 support as well as a recent issue that cropped up with the latest version of the plugin uploading other plugins' files. 

Please get in touch with @nelsonmc if you have any questions. We'd really appreciate it if you could give the changes a once-over to make sure we're not doing anything potentially dangerous. 

Thank you, 
—Mike