[ENH] vimeo: Allow remote files to be "uploaded" by reference (so a new file object links to the remote file).
Mostly makes sense for vimeo videos but with with other file types as well, currently only enabled if vimeo_upload: y.
Also fix input disabled input functionality and display errors to the user.

git-svn-id: file:///var/local/code.tiki.org/tikisvn/trunk@47359 b456876b-0849-0410-b77d-98878d47e9d5