Merge pull request #35 from betashepherd/master

add get server opt function,change $server->set to $server->setopt, update examples and wiki
revert setopt -> set
revert setopt -> set
Update: udp server
new examples file
Update: last udp port info
Update: use async swoole_client in fpm
Update: reset async_mysql check
fixed check eof Segmentation fault
buffer add length check
modify api
Merge pull request #36 from ewenlaz/master

add package length check