Bug fixes

• A critical MQTT heap-based overflow in parse_mqtt() fixed - credit goes to Yakun Zhang and Zheng Huang of Baidu Security Labs for discovering and reporting the issue
• mg_resolve2() incorrect memory init fixed
• Fixed locking in lwip_net_if
• Fixed callback invocation in mg_net_if_lwip

Features

• Added new platform rs14100, a multi-protocol wireless chip from Redpine Signals
• Deliver EV_CLOSE to the last endpoint handler
• Allow NULL handler for mg_bind and mg_connect