Upgrade node-http-proxy to 0.10.1.

Intentionally not choosing 0.10.2, which has a websocket proxying Node 0.10
semi-fix which I found to sometimes corrupt data (on Node 0.10). See my analysis
on https://github.com/nodejitsu/node-http-proxy/pull/402

I do not know whether or not the PR corrupts data on 0.8, but it isn't necessary
there, so I'm going to hold off on taking that change until the promised future
complete rewrite of http-proxy to use the new 0.10 streams API.
Merge branch 'upgrade-proxy' into devel