Add the URL to the HTTP response when it is logged in the same manner
that the URL is added to the request logging. The added logging adds
some additional clarity when reading logs that contain many
request/response pairs.
There's a few places where OkHttp could leak a connection that needed to be
closed. With our new connection pool model this is easier to find. This fixes
two specific problems:
- too many redirects doesn't release the last used connection
- interceptors that throw runtime exceptions don't release the connection
There are likely more situations. I have hacked together a small little test
harness to make finding these leaks easier; that's not included in this PR.
Also formalize HttpURLConnection-only 'Response-Source' synthetic header to be on par with the protocol header (which is retained for this legacy interface).
