fix #921 by passing socket.error on to the caller (where it will be ignored)
use six.reraise to amend the traceback
Remove no-longer-true statement about matching Nginx signal handling
Merge pull request #931 from laterpay/feature/921-ignore-async-handle_request-socket-error

Feature/921 ignore async handle request socket error
comment formatting
Merge pull request #936 from minichate/nginx_signal_docs

Remove no-longer-true statement about matching Nginx signal handling