v3.0.0-rc2

Breaking change:

• Server::Request::remote_endpoint_address and Server::Request::remote_endpoint_port
  are now functions to reduce unnecessary instructions. Also fixed issue with the
  previous variables that were not correctly set.

Noteworthy changes:

• Replaced readers-writer lock with a spinlock for stopping handlers
• Added noexcept keyword to functions
• Added gcc and clang flag -Wsign-conversion
• Added client support for Server Name Indication
• Fully removed boost dependency when standalone ASIO is used
• Added HttpHeader::parse to utility.hpp
• Added status code tests
• Modernized all CMakeLists.txt files, and made it easier to use
  Simple-Web-Server as a sub-project
• Added HttpHeader::FieldValue::SemicolonSeparatedAttributes::parse. This
  function can be used to parse Set-Cookie and Content-Disposition header field
  values
• Fixed compilation issue on Debian Jessie when standalone ASIO is used
• Fixed compilation issue for systems using older versions of OpenSSL
• Optimized the status_code-functions
• Added MSVC support to cmake files (not tested). Some tests are disabled due to
  lacking MSVC options.
• Added chunked transfer encoding support for incoming requests to server, in
  addition to cleanup of chunked transfer encoding functions.
• Client can now send chunked transfer encoded content