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.
It's a much simpler and clearer way of accomplishing the same thing.  The only difference between post and put is that a different "method" parameter is passed through to the perform() call.