Do not make throwing asio library calls from within async callbacks

The following asio library calls may throw, and we should not call them from within NetworkInterfaceASIO. Many of these methods have non-throwing variants:

asio::io_service::run()
asio::system_timer constructor
asio::system_timer::cancel()
asio::system_timer::expires_at(time point)
asio::system_timer::expires_after(duration)
asio::system_timer::wait()

This list may not be exhaustive.