tcp proxy support in malai http-bridge

[amitu]

http-bridge lets you access a malai http over http://<id52>.kulfi.site. We can do such that http://<id52>.kulfi.site can be used for accessing tcp services as well. Today there is no tcp-bridge, since tcp does not have any way to identify itself, but http does, http always has request, and request contains host to connect to, where we connect to over p2p, and forward the http request to. No tcp equivalent for this because TCP has no way to generically identify itself.

Solution, most applications support http-proxy when accessing TCP ports. So if we let HTTP_PROXY=http://<id52>.kulfi.site, work, tcp proxying problem is solved.