Plat 556 http rest proxy watching

When using this to watch (eg, etcd) it's difficult for debugging to have to catch exceptions, and we need to get data as it comes, not only once the connection is closed.

These changes allow for the HTTP Rest Proxy to be used in this context.
About the exception, AFAIK, curl does not timeout unless a timeout is explicitly specified. If it is, then it's fine with me.

About my suggested change, indeed, it would require to let the connection object live inside what the "Response" object currently is. That's why I suggest to do this only when time allows, if that is even worth it.