Fix for TCP connections not sending full content
Eventlet previously broke the standard API for sockets
and made socket.send() work in the same manor as socket.sendall()
reverted to the standard behaviour.
This was released as part of 0.18.0.
The bug manifests itself when large (multi TCP message) AXFRs are
performed over long distances.
(I replicated it when the messages grew to 3,
over USWest -> EU transfer)
for details on testing.
This change can cause packets to be dropped intermitently -
but retry will allow this to be overcome.
(cherry picked from commit f2c06477af)
(cherry picked from commit 6c49166b06)