Like existing ecore_con code, this does not use SOCKSv5 UDP
proxy. It's kinda cumbersome to add since requires a keep alive TCP
connection to the server, a second UDP channel and framing around the
original UDP frame.
Added UDP_CORK (if present) to match TCP_UDP present in TCP sockets,
this allows one to execute multiple write() calls that will result in
a single datagram, generated when CORK becomes FALSE again.
The efl_io_copier_example.c now accepts this as output. There is no
input UDP as there is no way to notify the server of a connection
(since such thing doesn't exit), usually servers react after a
datagram is received, replying to the source.
b36e2c65f6