[FOLD] unit test fix (return error_code from basic_parser)
[FOLD] whitespace (Use autotls instead of multitls)
Don't use MultiSocket in Overlay:
The MultiSocket is obsolete technology which is superceded by a more
straightforward, template based implementation that is compatible with
boost::asio::coroutines. This removes support for the unused PROXY handshake
feature.
Add [overlay] configuration section

Conflicts:
	src/ripple/overlay/impl/OverlayImpl.cpp
	src/ripple/overlay/impl/OverlayImpl.h
	src/ripple/overlay/impl/PeerImp.cpp
	src/ripple/overlay/impl/PeerImp.h
Always detect ssl in HTTP server
Add new Handler interfaces
Persist HTTP peer io_service::work lifetime
Add HTTP::Writer interface:
The Writer interface allows clients to supply a "pull" style object to provide
responses to HTTP Requests. The interface is designed to support a coroutine
based implementation.
Tidy up includes
Split implementation into three headers
Use ssl_bundle in SSLPeer
Call HTTP Handler with legacy peer handshake
Use ssl_bundle in Overlay::Peer
Construct Overlay::Peer with ssl_bundle and legacy handshake
Pass legacy peer handshakes through Overlay
De-pimpl HTTP::Server
Add Section::name:
The Section object now stores its name for better diagnostic messages.
Add doors section in cfg
Add [doors] parsing code
Rename to legacy_context