Connections were being garbage collected while they were still in progress
since the object would leave scope. This commit adds ObjectWrap::Attach()
and ObjectWrap::Detach() to tell v8 that an object is currently on the event
loop and will be needed in the future.
Other changes to oi_socket.c and net.cc are to fix bugs encountered while
running the HTTP server.
This might need to be changed in the future if ev is needed in thread pools
or extension libraries. However for now it makes sense to just use a single
loop.
