Remove unused classes
Fix clang warnings
Consolidate C++14 compatibility into new headers
Remove unused TextDiff
Fix beast::asio failures on OS X.
There are 38 unittest failures on OS X.  These changes address all of
them by adjusting which side of the socket (send or receive) gets
shut down.  In each case, the failure was 'Socket is not connected'.
I've interpreted that to mean that the other thread had already shut
down its side of the connection.
Merge commit '6c0edd2190bfd18ffc523f486367da3724cf98a3' into develop
Update http code for http parser API changes
Handle unexpected relative paths from __FILE__
Fixes comref#RIPD-133
Add C++11 noexcept compatibility for VS2013
Add beast::buffer_view
Add std::integer_sequence C++14 compatibility
Refactor beast::asio:
* New tools for completion handlers:
  - wrap_handler provides composed io_service execution guarantees.
  - bind_handler rebinds arguments to handlers.
  - shared_handler type-erases any completion handler.
  - buffer_sequence type-erases templated BufferSequences
  - abstract_socket replaces Socket
  - socket_wrapper replaces SocketWrapper
  - beast::asio placeholders to work with std::bind

* Removed obsolete classes and functions
  - AbstractHandler
  - ComposedAsyncOperation
  - SharedFunction
  - SharedHandler
  - SharedHandlerAllocator
  - SharedHandlerPtr
  - SharedHandlerType
  - SocketBase
  - SocketWrapperStrand
  - wrapHandler

* Refactored classes to use new tools
  - abstract_socket
  - socket_wrapper
  - HandshakeDetector
  - HttpClientType

* Miscellanous tidying
  - socket classes moved to beast::asio namespace
  - beast asio files provide their own namespace declaration.
  - Fix IsCallPossible conflicting template parameter name
  - Use <boost/get_pointer.hpp> for C++11 compatibility.
  - Remove extraneous include path from build environment.
beast, beast::asio improvements and fixes:
* New maybe_const_t alias for maybe_const
* New asio::enable_wait_for_async for safe cleanup
* New asio::memory_buffer, a managed boost::asio compatible buffer
* shared_handler improvements:
   - Can be 'empty' (no stored handler).
   - Default constructible as 'empty'.
   - Safe evaluation in bool contexts, false==empty
* Fix is_call_possible metafunction:
   - Works on empty argument lists
   - Works with reference types
* Replace SafeBool idiom with C++11 explicit operator bool
* Move IPAddress function definitions to the header
* Move cyclic_iterator to container/
* Remove unused BufferType
* Remove obsolete classes:
   - NamedPipe
   - ReadWriteLock
   - ScopedReadLock
   - ScopedWriteLock
   - LockGuard