fix#778
* The version data member is replaced with accessor
member functions.
Actions Required:
* Call member function message::version instead of accessing
the version member at call sites.
fix#778
* The body data member is replaced with accessor
member functions.
Actions Required:
* Call member function message::body instead of accessing
the data member at call sites.
* Stream write operations now return the number of bytes
transferred from the caller's input buffers.
Actions Required:
* Modify websocket write completion handlers to receive
the extra std::size_t bytes_transferred parameter.
fix#575, fix#604, fix#608, fix#634, fix#712
All examples are rewritten:
* Using Best Practices
* Mostly self-contained
* New examples to complete the feature matrix
* The server-framework example is removed
