Improve transaction security
* Check signatures of every transaction on every validator
* Remove obsolete code
* Check transaction status in submit/sign RPC handler
Set version to 0.26.3-sp2
Use trusted validators median fee
Set version to 0.26.3-sp4
Use autotls instead of multitls in websocket:
The MultiSocket class implements a socket that handshakes in multiple
protocols including SSL and PROXY. Unfortunately the way it type-erases the
handlers and buffers is incompatible with boost::asio coroutines. To pave the
way for coroutines this is part of a larger set of changes that roll back the
usage of MultiSocket to older code, and some custom implementations that use
templates. The custom implementations are more simple since they use
coroutines. Removing MultiSocket will make many other classes and source files
unused, a big win for trimming down the codebase size.
Workaround for MSVC stdlib and coroutine interaction:
If beast::Time::currentTimeMillis is first called from a coroutine launched
using boost::asio::spawn, Win32 throws an exception. This workaround calls
getCurrentTime once in main to prevent the exception.
Reference:
    https://svn.boost.org/trac/boost/ticket/10657
Add beast::asio::ssl_bundle workaround:
This works around the limitation that 1.56 boost::asio::ssl::stream objects
do not support r-value move or construction. It is required when the stream
does not own the socket.
Return error_code from beast::http::basic_parser:
This changes the HTTP parser interface to return an error_code instead
of a bool. This eliminates the need for the error() member function and
simplifies calling code.
Keep a list of section config values that are not key/value pairs:
This change to BasicConfig stores all appended lines which are not key/value
pairs in a separate values vector which can be retrieved later. This is to
support sections containing both key/value pairs and a list of values.
Remove HTTP::ScopedStream:
This class was used to allow stream style operator<< to write to the
HTTP::Session. This is being superceded by a more robust object-based model
that supports coroutines.
New JsonWriter for improved client performance (RIPD-439):
When JSON-RPC and Websocket responses are calculated, the result is stored
in intermediate Json::Value objects and later composed in a single linear
memory buffer before being sent to the socket.  These classes support a
new model for building responses that supports incremental construction
of JSON replies in constant time and removes the requirement that all
data returned be located in continuguous memory.
* New JsonWriter incrementally writes JSON with O(1) granularity and memory.
* Array, Object are RAII wrappers for the O(1) JsonWriter.
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. After this change a large number of classes and source files may be
removed.
Add [overlay] configuration section (experimental):
This configuration section uses the new BasicConfig interface that supports
key-value pairs in the section. Some exposition is added to the example cfg
file. The new settings for overlay are related to the Hub and Spoke feature
which is currently in development. Production servers should not set
these configuration options, they are clearly marked experimental in the
example cfg file.

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
Set version to 0.26.4-rc1
Revert "Add [overlay] configuration section (experimental):"

This reverts commit 856fd9d69f9b5d114982d9de361bcdf5ecbba505.
Set version to 0.26.2-rc2
Add missing includes
Fix incorrect socket closure in Overlay peers:
On Application exit, Overlay was calling PeerImp::close for each peer.
The implementation of PeerImp::close only canceled all pending I/O and did not
call functions necessary for proper transition of Peer state during socket
closure. The correct transition is ensured by calling PeerImp::detach. This
changes PeerImp::close to call PeerImp::detach instead, ensuring that Overlay
invariants are maintained. Specifically, that reference counts for pending I/O
on peers will be correctly unwound by canceling operations and that the Peer
object will be destroyed, thus allowing the Overlay to stop correctly.
Merge branch 'release' into develop
Set version to 0.26.4-rc3