http: support all connections contd.

include/opendht/dht_proxy_client.h

include/opendht/dht_proxy_server.h

include/opendht/http.h

src/dht_proxy_client.cpp

src/dht_proxy_server.cpp

src/dhtrunner.cpp

src/http.cpp

tests/dhtproxytester.cpp

tests/dhtproxytester.h

tools/dhtnode.cpp