Bug fix for the clean-up of removed poll fds, when  NN_USE_POLL is selected

Signed-off-by: Martin Sustrik <sustrik@250bpm.com>
Merge branch 'master' of github.com:nanomsg/nanomsg
Aram Santogidis added to the AUTHORS file

Signed-off-by: Martin Sustrik <sustrik@250bpm.com>
Merge remote-tracking branch 'upstream/master'