Notable changes:

• Time point when a request header is read is now stored in Server::Request::header_read_time
  
• Fixes to Percent::encode
  
• Header field values are now correctly parsed even with more than 1 space after :
  
• Now only adds port to host request header field value if the port is non-default
  
• Support for C++17 string_view
  
• Server::bind and Server::accept_and_run can now be called instead of Server::start, in order to access bound port
  
• Optimized string() functions
  
• Added checks to getline calls in parse functions so that they can be used outside the Server/Client classes
  
• Response::send calls now queue the messages sent to client. This enables simpler implementations of server-sent events.