Add a way to accept File Handler POST requests in an addin
Less complex file handlers need almost no server-side code, the only bit being the code to transfer the POST data to client-side code.
I suggest adding some way to get that information to client-side code that doesn't require writing custom server-side code - perhaps a directive that outputs it to a variable or something in the JS API.
This would allow simple file handlers to be hosted as an addin, without the need for external hosting.
