While these methods are marked unstable in libstd, this is behind a
feature flag, `timeouts`. The Client and Server both have
`set_read_timeout` and `set_write_timeout` methods, that will affect all
connections with that entity.
BREAKING CHANGE: Any custom implementation of NetworkStream must now
implement `set_read_timeout` and `set_write_timeout`, so those will
break. Most users who only use the provided streams should work with
no changes needed.
Closes#315
7d1f154cb7