[x0d] echo_example adapted to recent API changes
[plugins] director: fixes SEGV caused by GET requests to the director API
[plugins] director: fixes 'GET /:director/backends/:backend' output
[base] BufferSource: add some convenience accessor to its internal buffer object, for deferred population after BufferSource has been constructed
[http] HttpConnection: improved writeSome() operation, more opportunistic write action
[http] HttpConnection: fixes the start()-bug wrt "Expect: 100-continue"
[http] HttpConnection/HttpRequest: request body processing simplification
[http] HttpRequest: consumeBody() -> takeBody()