be_sock: handle readv() returns ECONNREFUSED (freebsd 9.2) During testing sometimes bufferevent/bufferevent_connect_fail_eventcb fails, and after some digging I found that this was the case when connect() doesn't return ECONNREFUSED immediately, and instead next operation will return it (in our case evbuffer_read()->readv(), needless to say that after this bufferevent_writecb() called and it checks error with getsockopt() but of course it doesn't return any error), so this patch checks "errno" after "readv()" and installs "bufev::connection_refused" flag, to handle this from writecb and only once. Fixes: bufferevent/bufferevent_connect_fail_eventcb Fixes: bufferevent/bufferevent_connect_fail_eventcb_defer Refs: #388