greenio: Remove sendall-like semantincs from GreenSocket.send
greenio: Remove sendall-like semantincs from GreenSocket.send

When a socket timeout was set the sendall-like semantics was resulting
in losing information about sent data and raising socket.timeout exception.

The previous GreenSocket.send() implementation used to call fd.send() in a
loop until all data was sent. The issue would manifest if at least one
fd.send() call succeeded and was followed by a fd.send() call that would
block and a trampoline that timed out. The client code would see
socket.timeout being raised and would rightfully assume that no data was
sent which would be incorrect.

Discussed at https://github.com/eventlet/eventlet/issues/260.

collinstocks/eventlet,collinstocks/eventlet