Add HttpServerResponse.writeRawBody taking an InputStream and improve request/response logging.
Fix character encoding of default error pages + improve writeRawBody(InputStream).
Rework the HttpClient to allow reading of the raw body response + improve request logging.

The raw reading functionality is useful for proxies that want to pass the reponse on without decoding it. To make this work, HttpClientRequest.bodyReader is now a property that is initialized lazily.
The HttpProxy now passes on responses with Content-Length unmodified and does not suppress the CL header in it's own response.

The suppressed Content-Length header caused at least Chrome to ignore the Content-Encoding header, resulting in corrupted downloads. Passing on the body unmodified should also increase performance considerably. Extending this to work with chunked transfer encoding will be the next optimization step.
Merge branch 'master' of github.com:rejectedsoftware/vibe.d