[Catalyst] [PATCH] C-P-UploadProgress (converted away from NEXT)

Hey Andy, and general Catalyst guys.
Attached is a patch to convert Catalyst::Plugin::UploadProgress into
using Moose::Role instead of NEXT, since the latter is deprecated as of
Cat-Runtime .18.

Could you have a look over it? I'm not 100% sure the first function is
"good" since it's never calling super() from inside prepare_body_chunk.
But hey, that's just how the original code worked too..

Cheers,
Toby