Unable to build goby2 on RHEL/CentOS 8.

[cgagner]

Unable to build goby2 on RHEL/CentOS 8.

There are three main issues with compiling on RHEL/CentOS 8:

1. boost::asio::io_service was deprecated in 1.66. Replaced with boost::asio::io_context.
2. boost::asio::basic_stream_socket native() method deprecated in 1.47. Replaced with native_handle().
3. Using proj_api.h is deprecated. Can be enabled by defining ACCEPT_USE_OF_DEPRECATED_PROJ_API_H.