Important: security fix for Client: added host verification
Other improvements:
- Added threaded heavy work example
- Added io_test and CI
- Added install target
- Replaced class visibility private with protected
- Force TLS 1.2
- Added exception handler to handle exception throws in Server
- Less copies of shared_ptr objects
- Possibility to set or reuse boost::asio_ioservice
- Use of std::regex with clang and g++ if possible
- Improvement of default_resource example
- Timeout can be set on client requests
- Various MSVS fixes
- Added proxy server support to Client
- Various minor bug fixes.