git-annex can proxy for remotes that are accessed locally or over
ssh, as well as special remotes. But, it cannot proxy for remotes that
themselves have a annex+http annexUrl.

This would need a translation from P2P protocol to servant client.
Should not be very hard to implement if someone needs it for some reason.

Also, git-annex could support proxying to remotes whose url is a P2P
address. Eg, tor-annex remotes. This only needs a way to 
generate a RemoteSide for them.

(This is a deferred item from the [[todo/git-annex_proxies]] megatodo.) --[[Joey]]

