Remove code duplication in Socket.cpp: Merge parts of Socket::Send() and Socket::EndSend(), which now use same codepath on both Windows and Unix.
Remove code duplication in Socket.cpp: Merge parts of Socket::Send() and Socket::EndSend(), which now use same codepath on both Windows and Unix.

juj/kNet,nonconforme/kNet,juj/kNet,juj/kNet,nonconforme/kNet