WebSocket++/0.6.0

• MINOR BREAKING TRANSPORT POLICY CHANGE: Custom transport policies will now be
  required to include a new method void set_uri(uri_ptr u). An implementation
  is not required. The stub transport policy includes an example stub method
  that can be added to any existing custom transport policy to fulfill this
  requirement. This does not affect anyone using the bundled transports or
  configs.
• MINOR BREAKING SOCKET POLICY CHANGE: Custom asio transport socket policies
  will now be required to include a new method void set_uri(uri_ptr u). Like
  with the transport layer, an implementation is not required. This does not
  affect anyone using the bundled socket policies.
• MINOR BREAKING DEPENDENCY CHANGE: When using Boost versions greater than or
  equal to 1.49 in C++03 mode, libboost-chrono is needed now instead of
  libboost-date_time. Users with C++11 compilers or using Boost versions 1.48
  and earlier are not affected. Note: This change affects the bundled unit test
  suite.
• Feature: WebSocket++ Asio transport policy can now be used with the standalone
  version of Asio (1.8.0+) when a C++11 compiler and standard library are
  present. This means that it is possible now to use WebSocket++'s Asio
  transport entirely without Boost. Thank you Robert Seiler for proof of concept
  code that was used as a guide for this implementation. Fixes #324
• Feature: Adds a vectored/scatter-gather write handler to the iostream
  transport.
• Feature: Adds the ability to defer sending an HTTP response until sometime
  after the http_handler is run. This allows processing of long running http
  handlers to defer their response until it is ready without blocking the
  network thread. references #425
• Improvement: echo_server_tls has been update to demonstrate how to configure
  it for Mozilla's recommended intermediate and modern TLS security profiles.
• Improvement: endpoint::set_timer now uses a steady clock provided by
  boost::chrono or std::chrono where available instead of the non-monotonic
  system clock. Thank you breyed for reporting. fixes #241
• Improvement: Outgoing TLS connections to servers using the SNI extension to
  choose a certificate will now work. Thank you moozzyk for reporting.
  Fixes #400
• Improvement: Removes an unnecessary mutex lock in get_con_from_hdl.
• Cleanup: Asio transport policy has been refactored to remove many Boost
  dependencies. On C++03 compilers the boost::noncopyable dependency has been
  removed and the boost::date_time dependency has been replaced with the newer
  boost::chrono when possible. On C++11 compilers the boost::aligned_storage
  and boost::date_time dependencies are gone, replaced with equivalent C++11
  standard library features.
• Bug: Fixes a potential dangling pointer and inconsistent error message
  handling in websocketpp::exception. #432 Thank you Tom Swirly for the fix.