Integrate file upload with workflow around package resources

[rgrp]

Create/edit a package -> add a resource -> Oh, i haven't uploaded yet, 'upload here' -> /upload -> standard upload form

Do we need to create a resource out of the file after upload? Do we sync file metadata with local Resource metadata?

If yes suggests (need to ticket):

• 'ResourceExtras?' for extra metadata on resources
• Makes 'Resource' into first class object (and make available in WUI)?