Fixes#3740
In the case of pipelined requests, you can have a situation where
the socket gets destroyed via one req/res object, but then trying
to destroy *another* req/res on the same socket will cause it to
call undefined.destroy(), since it was already removed from that
message.
Add a guard to OutgoingMessage.destroy and IncomingMessage.destroy
to prevent this error.
test/simple/test-url.js:31:(0110) Line too long (82 characters).
test/simple/test-url.js:39:(0110) Line too long (85 characters).
test/simple/test-url.js:40:(0110) Line too long (92 characters).
There is a difference between errors which happen to a socket - like
receiving EPIPE - an exceptional situation but ultimately okay and the
situation where code throws in a callback - which is not okay.
Fixes test/simple/test-http-exceptions.js
TODO: explain this in docs.