The Socket_io_channel class now uses the Io_channel_backend to provide
the network related methods. In addition the Socket_io_channel_registry
was replaced with a simpler implementation which uses Io_receptors to
unblock I/O channels from the callback-function of lwip.
Programs use the errno value to check which error exactly occured.
It is mandatory for non-blocking I/O, e.g. connect() gets the current
state of the connection by looking at the returned errno values.
Fixes#337.
Noux/net adds network functionality to noux. Currently most basic
network related system calls including 'accept', 'bind', 'connect',
'listen', 'recv', 'send', 'shutdown', and 'socket' are implemented by
wrapping lwip's network functions.
At the moment noux/net is rarely usable, though it is possible to
use netcat to send a message to a netcat server which listen on a
given port in noux/net.