fix kqueue can't add multi event onetime, modify struct event fromm freebsd11 to freebsd13.
Update LICENCE.
Upgrade f-stack.conf in Nginx.
Support DPDK 20.11.0(LTS).
Bug:CLR_FD_BIT is undefined
User APP can use AF_INET6/PF_INET6 directly whether call ff socket or linux API, such as inet_ntoa/inet_aton.
Add executable permissions to configure of nginx-1.16.1.
Nginx: upgrade to 1.16.1 for HTTP/2(CVE-2019-9511, CVE-2019-9513, CVE-2019-9516)