swift: inline swift::proxy::config

Despite what the comments say, swift::proxy::config is only used by
swift::proxy. Having it external makes us jump through some hoops
(virtual resources, scope.lookupvar etc.) that are unnecessary, so just
inline it and cleanup.

Change-Id: Idf1dad8f7fae8f9b5fd7bedad97b15b64f85776e
swift: add statsd support to proxy-server

Enable statsd support, starting with proxies (object/account servers to
follow). Point to the newly provisioned tungsten as our working statsd
server.

The abstraction layers aren't very good but this is needed to remove the
logtailer machinery, which is a tad more important :-)

Change-Id: Id7920d2dabcf996520ad2dd88c8e7232b4078853