swoole-1.8.3-stable

• Added swoole_server->getLastError method for getting the last error code
• Added form-data supports for Http2 protocol
• Added COOKIE support for Http2 protocol
• Added SSL/TLS encryption support for http client
• Fixed issue #527
• Fixed issue #553
• Fixed crash when the number of CPU cores than is set reactor_num
• Fixed swoole_client callback function memory leak
• Added support for asynchronous full reload of server security