Disable buttons while waiting for POST response

[bentsherman]

This is a pretty broad issue. Any button on the website that sends a POST request (saving/reviewing an album, submitting fishbowl reviews, etc.) should probably be disabled while waiting on the request. That way the user can't click the button more than once out of impatience.

This issue came up particularly with the Fishbowl Control Panel, because senior staff would click "Submit" two or three times, so their ratings would be weighted more heavily than others. That's not a huge deal, but for heavier operations like importing an album, this feature might be more important.